<human>: Can you condense the text into three sentences or less?

So I (20m) broke up with my gf (19) last night and I want to know if there is some actual explanation of what I am/was feeling. We had been dating almost 2 years and she was my first real girlfriend. Since then we've been through a lot together moving out of our respective parents houses and back because of family drama, she's been the only person I've ever opened up to and I still feel closer to her than anyone I've ever met I still love being around her and talking with her but we've gotten so close I've lost the intimacy that I had with her for some reason the drive for sex and kissing just isn't there any longer and I feel like this is a problem I've had my whole life

Even when I was a child I would fluctuate between complete obsession and indifference in everything I do/did it holds my attention for a while and when I'm done its over I just don't have any feeling left when it came to material thing and when it came to people emotions and feelings just weren't there I never had close friends as a kid and even family was just blah I mean plenty of my family I find to be enjoyable company but if I never saw them again honestly it wouldn't really effect me I haven't spoken to mother in 3 years I've only talked to my only brother a couple of times since then and while I live with my father our lives don't really cross I spend my time with who was my girlfriend and he spends his time with his new gf

So after talking and reaching that conclusion I told her that I do still care about her and that I will always be there for her but the love has changed so we decided that we would try to be just best friends which is pretty much how I love her.

So my question is what is wrong with me I still find her physically attractive and intellectually engaging but its just like someone flipped a switch and turned off the relationship part. Further I'd also love to know if anyone has been in this situation on either end and how it played our
<bot>: I just broke up with my girlfriend of 2 years and don't know why I lost the spark and want to know if this is common or if being relatively emotionless is odd and what to do