Relationships are overrated
Seriously though, I think you have recieved a lot of good advice here. And I know that simply saying "Stop being so jealous!" is not going to help matters either. It just seems that you put too much of your mental imagery and thought into wanting a relationship that it overwhelms the rest of your life. Dwelling on not having one is making you miss out on so many more important things. And might I add that your over the top desire for a relationship probably hinders your ability to be able to have one, and from what it seems from talking to you, I don't think you are READY for one.
You need to concentrate on the more important things in your life right now, put relationships on the back burner and give the therapy a chance to help you. Give yourself a chance too. Believe that you can find a better place and don't give up on yourself, because if you don't believe in yourself then what good is wanting change?
The JW's have the concept of "faith" wrong. And I don't care what the bible says, even though you may see in yourself no hope and no reason to believe, you have to have faith anyway and act as if your life change, no matter how much you don't believe it, just do it. Put forth the effort to make change no matter how worthless you think that effort is.