Sorry if there are some assumptions on my part mysterysolved...
Firstly, evidently you are aware there is an issue, and self awareness is always the key to taking control of a situation. And that's what you need to do right now, right?
I see that you are a four. E4 has an inclination to withdraw especially during stress (which is going to be compounded by introversion). Are you under stress (from the external and/or internal) right now M.S?
You may need to go back and look at the cause and effects leading up to where you are now. How did you reach this point and why? what are your general tendencies of coping with stress and why have you chosen this path? is it because it is effective? or is it because it feels safe?
e4s' have a tendency to escape into their fantasies and relive and highten emotions, while e5s' escape into their ideas. All of it involves withdrawing into the mind. When you do this, it's like rejecting the external. A fight or flight mechanism. It feels safer to exist in your mind, because there's something happening in the external that's threatening. If you become too much in your head, you might fall into the trap of a fi+si loop. And you can see that these both are introverted functions. You might rely on taking too much information from the inside, and also judging it from the inside. There's no external information or judgment channeling through. There's a fundamental imbalance... because relying too much on the inside leads to a great disconnect between the internal and external. And even though you need the balance, you can't obtain it because the external feels unsafe.
I think breaking the cycle is an individual battle. But what I would advise, is to stay attached to the external in some shape or form. Don't let yourself stray too far away from the outside. Keep in contact with trusted people. Ask for their feedback. See a counselor and ask for their feedback if you don't have anyone. Stay involved with society in some shape or form. Volunteer, work, or regularly keep up with the news and world events. Don't completely withdraw from everything for too long. Keep your channels of extroverted perception information open. Take baby steps so it doesn't send you into shock. Little steps at a time.
The simplest exercise for Ne would be brainstorming. Be aware of your thoughts. If you catch yourself judging too quickly, tell yourself "no" and keep yourself open to new information. Consider all the possibilities.
If there's a deeper problem, it's best to let someone know. If you become too detached from reality, sometimes you need help to get through it. A lot of people have been in this situation

and i'm sure there's people out there who would be willing to help you.