Wish I could say something more upbeat, but I'm still ruminating on things people told me when I was five years old. That was... well, it was more than two years ago.
Therapy has helped, but there's a catch: I think I went to maybe five or six doctors before I finally found someone I could connect with. If you don't find someone you can trust enough to bare your soul to, the therapy really doesn't do much. Each of those doctors was more than willing to do the hand-holding and the "You'll be all right"ing, but none of it did me much good. The one I formed the rapport with was the first one to say, "Well THAT'S a weird way to interpret that. I don't think it's half way as bad as you think. Let me ask you some questions about..."
This is going to sound strange, but one of the most reassuring things they did was to tell me that if at any point they thought I was at risk of harming myself or anyone else, they would place me in protective custody. So when I told them about a particular obsession wherein I see myself stabbing the people around me, I expected them to pick up the phone. They didn't. They heard me out and we talked about it. Afterward I asked why they didn't make the call. They told me because other clues I was giving them told them I wasn't at risk of acting on it. I'd never realized that, myself. I'd always thought I was a monster. They told me I wasn't. I broke down and cried. I still get that obsession from time to time, but it's not nearly as scary as it used to be, because of what they said.
So yeah, therapy can help. But you can't hold back if you go that route. Tell them everything or find a new therapist and tell THEM everything. Don't go half way.