Why do I lose at love?

I am alone, never been kissed, nearly a 40 year old virgin.Currently no job and I live at home. What I used to want most in the world was a wife and kids a great job and home. Seems life has passed me by. I remember confessing my love for a friend almost 15 years ago when she was in a bad relationship and i got turned down. It broke my heart inside but I carried on like normal. She went on to date some other guy kinda short , a bit obnoxious at times, and i believe less attarctive than me. What The heck?!!!! I hung out with them at the movies once. Maybe they just invited me as a joke. Another time i backed out for legit reasons but she got a little ticked off and i guess didn't believe me. i lost their contact info and never heard from them again. And she gained weight and married the guy I do believe. Yet still I think of her with some regret but mostly anger. I don't understand how she could do that to me. There were a few other gals most i met online but it never worked out. They didn't wait for me and chose other guys or were in love with other guys. Now sometimes I feel like i dont know how to love anymore or i'm afraid to love, like it will all just end in disaster. I wish i could change the past. I've been depressed lately and unmotivated about my life and suffering from anxiety i believe. I had a panic attack /breakdown in july partially due to a lack of potassium. I never told anyone. I haven't been 100% since. I'm like 95% and that 5% that is missing scares the living hell out of me. I feel like I could lose it all. Like I might unravel . Sometimes now when I feel overwhelmed I have to lay down and sleep. It seems I have lost everything and now my mind. I think if I had someone to really love me I'd be better off, but I don't know what to do or how to find that person. She could just lie beside be and asure me that she loved me and encourage and motivate me. What do I do.?