I'm guessing this is a BPD trait?

Sometimes I think I'm straight, bisexual, gay, or asexual. It's so weird. For a long while now I have assumed that I am asexual because I don't care about sex and don't want it. I could go through my whole life without it and I wouldn't care. I don't find anybody sexually attractive anymore, although there's this one girl (who's my favourite person and we aren't close, unfortunately, but I used to be obsessed with her and think about her every day) and she teases me quite a lot (despite having a fiancé and is straight, I think) and sometimes I fantasise about doing things to her in my head (kissing and touching, mostly). I don't really get turned on by it, but the thought excites me (?). I was also extremely sexually attracted to my second boyfriend and a simple kiss would arouse me. I haven't felt the same with any guy since then (early 2016) and have mainly been thinking about girls. I have been thinking more of girls for years now (I thought I might have been a lesbian), though, but lately I have thought of nobody. I can't even remember the last time I was turned on, so I assume I'm asexual. Thing is, I suffer from severe depression which has made me lose interest in everything I once enjoyed and have a feeling this may have something to do with it, but I'm not sure. Ugh, anybody else relate? Sorry for making lots of threads here, guys, haha.