First, OCD isn't just having thoughts -- it involves compulsive behavior. All mental disorders and many mental states that aren't disorders involve intrusive thoughts. I can't really say any more than what I already said -- it's perfectly normal at your age to have such thoughts, but if you're unhappy with how things are going, you need to find a good therapist to talk this through with, as it sounds like there's a lot of grief and stuck thinking going on -- you say you don't do change, but every day is a different day so change is the norm. A good therapist might be able to help you through this. Good luck.
I have liked boys since I was a child. I have nothing against being gay, but I am not gay myself.
I have had OCD thoughts on having HIV,
I have never thought of being gay and have lots of gay friends. I have been through so much change and now severe depression and anxiety. I know me and this isn't normal for me.
This isn't necessarily anxiety at all -- this is normal behavior and thinking for your age, though it usually happens a bit younger. Most of us go through this thinking as we get exposed to new ideas about sexuality and find life getting more complex. You may in fact suffer from depression and anxiety, but this isn't part of it from what you describe. Life will never again be perfect or easy -- the price of getting older and your brain getting more full of ideas and thoughts. But think of it this way -- perfect and easy is mind numbing, too, so if you ever want to accomplish anything you have to have that brain churning. But if you do have depression and anxiety and not just thoughts of life being confusing and difficult, which it actually is, then it might be time to see a therapist to talk it out. As for sexuality, that will take care of itself, but when you say a relationship was "perfect," well, was it really perfect? Or just good? Perfect doesn't really exist. Peace.