I'm a very jealous person.
And although it is useful to know yourself, you use a dangerous method here. You are rehearsing. You are repeating a mantra that you can believe.
The verb 'to be' is inappropriate because it is simply incorrect. A person IS NOT an emotion except as a temporary state. So the proper verb must be amended with an adverb, like, 'feeling', as in ... I am
feeling very jealous. That is possibly correct. When you do this you can realize that all emotions are a temporary state of being.
That leads to the next step, the truth that NO ONE but you controls and is responsible ultimately for what you feel. Even if someone slaps you or attacks you in other ways, YOU, are the one that causes and CHOOSES your feelings.
Yes, this discipline is hard but it is actually more natural in some ways than the foolish external causation of emotion most people believe in, much to their detriment.
I'm jealous of people's looks and achievements (can't even be happy for them most of the time).
Mostly I feel like I'm lover/friend-jealous though (a friend hangs out with another person or a person I like gives someone a heartfelt compliment and I'm instantly hurt).
There are many reasons for the overwhelming nature of jealousy. In the case you mention here it is two emotions at work, anger and desire. I will explain.
Desire is the main issue. Desire is the emotion of chaos and the future. Desire FORCES you to live in the future. That is because you want what you do not have now. That is foolish, in general. The only thing that you should want that you do not have now is to behave in a more moral way. Morality, choosing its path actively, is the ONLY thing that affords a person happiness. This is wisdom. This is truth. Deny this at your peril.
So desire involves all forms of shame, including jealousy and envy, which are distinct. But they are all desire, and specifically overexpressed desire refelcting back upon you. You see the issue is, if you want something you are telling yourself, rehearsing, that you are not by yourself intrinsically enough. That is morally incorrect. So this immoral choice WILL ALWAYS make you unhappy.
In the case of jealousy, the over expression of desire is something I have named, worthlessness wallowing. You sit in that emotion of worthlessness and the feelings are intense. You rehearse them as a pattern. You get used to that pattern. And you repeat that pattern. You become addicted to the pattern, the feelings of over expressed desire.
You see desire is part of love, one third of love, in fact. Anger and fear are the other two thirds. Each part of love is designed to reward you with happiness feelings when you pursue that part correctly and strongly. So you are pursuing desire very strongly, ... you fool. I am being coy now and not mean. Do not take it that this is mean, please. You are a fool for love. You have never heard that expression before right (more coy). So how do you stop? Will you stop? Can you want to stop? Yes, you can. But it is all you. It is all your choice. All feelings are all you, all your choice.
So you must realize the pattern. You must accept that this pattern is truth. This is what you are doing. If you accept it, you can blame yourself, and you are empowered then to decide to change. That is wise. I recommend it. So, you decide to change. You accept that it is your fault, that you are choosing to wallow in worthlessness. Some part of you desires to keep doing this. Your desire is getting its reward as designed by love. And its killing you with jealousy. Why?
The reason is ... anger! That is why I said anger before. You lack anger. You lack balancing anger.
Love is all emotions. But love includes evil. That may not be the typical definition of love, but it is the right one. GOOD is what people mean when they say love. But good sounds placid, boring. It is not. Good is BALANCED anger, fear, and desire.
Passion is at least slightly imbalanced desire.
Compassion is at least slightly imbalanced anger.
Friendship is at least slightly imbalanced fear.
These are the three types of love coming from each emotion.
So back to anger. Why is anger compassion? And why do you need it? Anger is the emotion of the present tense. It pushes back against fear and desire both and says ... FIND BALANCE ... and exist RIGHT NOW. And anger is correct. Anger is more honest with you than fear or desire can be. But each emotion MUST morally be used to balance the others. Fail in this and your actions (not you - avoid the verb to be) are immoral.
Further, anger is not only balance but it is fairness. Each person effectively DEMANDS their space just by living. Existence, being, all by itself, is violence. So violence is moral. Compassion is called the empty love. It is the angry assertion that every living thing intrinsically deserves its life and space and morally a fair share of ... ALL. Compassion is correct, just like passion and friendship are correct. But each of these if over expressed can lead to immoral imbalances. But love is NOT aware on its own, or ... best to say ... love has known patterns. Love rewards expression of emotions according to strength. So it can fail and thus love includes evil. I think I mentioned that before. Love REWARDS your wallowing in desire with intensity. Is love wrong? No, it is you that is wrong.
You are choosing, despite loves warnings, to wallow, to continue to wallow, in negative emotions. It is always your choice that cause you to suffer. It IS NOT other people's choices, and it IS NOT love's. Love forces free will upon you. It is YOU that chooses (what you do and feel).
So, what do you do?
You use more anger.
Why anger?
Because you DESERVE your space and happiness in this world. And you DESERVE for desire, your own desire, to stop over expressing itself. But desire is GOOD. Love rewards it. So you need balance. You need anger at your desire. Then you do not have to stunt your desire. You can live fully. Let your desire out of its cage. But anger, your anger, that you also let out of its cage, will automatically balance and restrain desire.
You anger will demand your right to be, regardless of your capabilities and traits. Wisdom is the only real trait you need. Every single person is better or worse than every other one in one to one comparison. So what? Love demands, via compassion, that you are equally worthy. That is a moral belief. Disbelieving that is immoral and will cause you pain. THAT is your weak anger. Some part of you attaches too much worthiness to function or traits. Worthiness via love is intrinsic, first towards yourself, and then to ... ALL. That is the demand of moral love.
I'm pretty sure there is some kind of inferiority complex and fear of abandonment behind it.
I find jealousy to be a very painful emotion and I would love to not feel it (or at least not so often and so "extreme").
So now i wondered...
Why are some people more jealous than others?
and are there some "methods" to "reduce" jealousy?
or is this just a stfu Kommandant get your shit together thing?
Any kind of advice would help.
DO NOT wish not to feel. That is immoral nihilism. Love demands you feel and balance your emotions to be wise.
Unhappiness is suffering your own choices. Choose otherwise. Unhappiness is a guide for you to change your choices. Process the emotion and move on. Get back to balance.
Watch carefully successful couples. They are happy. But that happiness is balance. They may gush and enjoy times of passion, but they accept that from one another because most of the time they are balanced. Imbalanced passion is addiction or desperation. It is immoral weakness. Use anger, use fear, and come back to balance. You can do it!