Slick,
Alright, well let me tell you that what you are doing now is the step in the right direction. Instead of trying to bury your issues with "I'm a DJ, I'm confident, I'm the man" affirmations that we both know hold no water, you're starting to identify that you have some issues. That's GOOD.
1) Figure out what feeling of insecurity, what FEAR the first girl that you went out with for 4 years, installed, and solidified in your mind. Is it fear of abandonment, deception, lack of trust, lonelyness, invalidation? What did she make you feel that has lingered with you since then. Identify the EXACT feeling that it has snowballed into.
2) What is it about having SOMEBODY around; girls, your wingman, etc that makes you feel 80% more confident? What voids to you think they fill that makes you feel more alive?
When you've figured those out; think about what you truely WANT. Do you want an LTR? Do you want to find a girl that you can share something special with that may evolve eventually in an LTR? What is this girl like, if you could choose? Figuring out what it is you want usually helps you identify it when you see it.
When you've done THAT, realize that the girl, the wingman, and the girl you are searching for are nothing but illusions, really. The girl that you dated that hurt you; only hurt you because you gave her the power over your emotions to do so. There is nothing wrong with feeling for somebody, but when you depend on them to fill some void, and they abandon you, that "crutch" that you've been leaning on to feel good...snaps; and you're left falling down into depression.
And what's even worse is that once you are depressed, it feels better to wallow in it. Right now you need to pull yourself out of that. You're producing negative results because you have a negative mind-frame. Change that, switch your paradigm, to a more positive one, and you'll find that it'll manifest (create itself) in reality.