When you genuinely love someone

Hello everyone. Just thought I'd share. This is a long story, sorry. About two years ago I started seeing a girl who I'd known since I was thirteen years old (22 now). We always liked each other but I never let it get beyond just being friends, she's been through a lot of bad stuff and I didn't want to use her. She also has a problem with being promiscuous, and even though I used to be promiscuous as well and didn't judge, I didn't want to be part of the problem. I cared about her too much. Years go by, we talk infrequently. As it happens, my best friend starts dating her best friend. She starts showing up at my house all the time, essentially trying to seduce me. At times I was very cold in rejecting her, but she had a kid who was less than a year old and was still with the dad. It bothered me, hurt even. This goes on for a long time, like over a year. Our friends get married, we're in their wedding. She tells me her and the kid's dad aren't together anymore and that she really wants me, that I'm basically the perfect person for her. At this point, I give in. I'd known her for so long, I had such strong feelings for her. I loved her son, and related to him because my parents split when I was his age. I had a terribly abusive stepfather and I wanted to be a great one for him. I realized that I loved her more than anyone. I never wanted to be with anyone else. And yet, our relationship just kind of ended. For over a year I can't even be happy. I think about her constantly, I miss her every waking moment of my life. But she doesn't care. The last time we talked she was incredibly mean to me for no reason. Her best friend, my best friend's wife, tells me she was seeing other guys almost the whole time we were seeing each other and that she doesn't think she loved me. Needless to say, my heart has been broken so badly that I'm not sure if I will ever be able to have a 'normal' relationship. Or trust anyone. I'm actually seeing someone now (not dating) and I really like her and care about her a lot, but I still can't move on. And I waited a long time to be with someone else, (a year and six months) I didn't want it to be a rebound. She deserves better than that. I've told her about all of this and she's very understanding. I'm trying to be better but what can you do? I have trouble with intimacy now. We've had sex and it was good but now sometimes I have a hard time getting an erection. I've never had that problem before. When me and first girl were together she said I was a 'horn dog' and I really kind of was. I could cum once and keep going until I did again, non stop boner (lol). I think it is partially because of porn and too much masturbation, but I've been watching porn and jerking off since I was nine. Not an exaggeration. I'm very adamant about about no more of that, but that's not the biggest issue here. No amount of sex, porn, masturbation, channeling the pain into creative energy, et cetera, has made me feel any different. I want to let go but it's just not happening. Even when I think about all the bad stuff and know that she wasn't right for me and wasn't worth all the time I wasted, I still love her unconditionally. I wouldn't be with her again, even if she apologized for everything and meant it. I don't want to be with her. I don't even care about talking to her. I worry about her son, but that's it. And yet the fallout of our relationship is still weighing me down. I wonder if I'm just not meant to be in a relationship. It sure feels that way. What sucks is that I used to be ok with being alone, but now I'm not such a fan. Thanks for reading this far.