I know this sounds cliche, but take some time off. It may be hard, and there will probably be sleepless, cry-your-eyes-out nights that will make you want to go back with this guy very much. The thing you have to remember is that it is over, and there are other people out there. Dating someone because they look like/remind you of your ex is not fair to you or the person you are dating.
It's never a good idea to break up and jump into a rebound relationship; they just don't work out well. Instead, try to find activities you like to do, something you can do by yourself and still have fun. If something reminds you of your ex, just accept that it does and go on with your day. It's easier said than done, but it will ease the pain if you accept how you feel and don't run from it. Accept it, then move on. Another guy right away, no matter how comforting it can be, is not a good idea. From what information you've given me, it seems that you aren't over your ex and most likely won't be for a good while; another guy in your life is not going to change that fact. Do some soul-searching, if you want to call it that, and get a little more comfortable in your own skin. Try some new things that you hadn't tried while you were with your ex. Go out and be social with new people (it's funner and easier than it sounds).
I hope I helped a little, and I'm sorry if this seems a tad blunt. I'm normally a little softer than this, but lack of sleep and limited patience with everything today makes for a rather snappy and short-fused me.