I want a girlfriend thats all no marriage?

See this is how it is for me. I'm lonely but not because I'm ugly I mean I'm over weight a little but I played football and ate like a champ but would run it all off in practice. So high school is out I was bound to gain a little weight I mean come on me excercise went out the window but me eating habits stayed the same, but I'm on the right track again eating moderately and working out again. I just seem to have lost all confidence. On a normal day I'm a freaking stud and I can talk to the ladies and I'm well versed in my conversation I talk to them not at them, but as soon as I find out they are talking about liking me I clam up. I get cotton mouth to the point of severe hesitation. I think it has something to do with the fact that my ex wife told me I wasn't worth it and I would be hopeless. I know that's just an excuse but I have missed out on two great girls and one has recently became single that I would love to make my girlfriend in the long run I'm just scared is all any tips?