Am I perverted?

A few years ago I was diagnosed with OCD but recently it was a pretty minor part of my life. About a month ago I came out to my boyfriend about how I sexually experimented with my brother when I was younger and he took it really badly. That made me incredibly anxious and now I just get obsessive thoughts about tons of different things. The ones that bother me most are the sexual ones because after my boyfriend reacted so badly to me, I can't shake the feeling that I've done something wrong and that I'm sexually bad in general.
I get thoughts about my dad, my brother, and children. The worst part about them is that sometimes they actually are accompanied by a little bit of arousal. I don't think this makes the thoughts more valid because the arousal only ever starts after I start getting the thoughts, and also because I was once very afraid that I was pregnant and whenever I read about a symptom it would appear, so I think my body just does whatever it's afraid of. It's still very scary though.
The worst part though is that one time I think I was legitimately aroused by a girl who was about 11. I was looking at her legs and they were shaped more like that of an older girl rather than a young girl, and I also thought a girl about 12 was a little pretty in a sexual way (I'm 16 btw.) These are isolated though and I wonder if it's maybe normal to have one or two isolated things like that since I'm not an adult yet? I think that's the only thing I really need assurance on. I know I'm not supposed to seek reassurance and my brain will just deny logic anyway, but I think I just needed to let it out. I don't feel safe at all telling any of this to my boyfriend because he acted like I was a sexual abuser when I told him about what me and my brother did, but it also makes me afraid to hide it from him. But I'm really too scared to tell him, mostly about the last part (the girls were his nieces.)