Personally, I wouldn't worry too much about labels like PTSD. (I say that, but I've been worrying a lot about myself and looking for the perfect diagnosis that exactly describes me!)
We all have a "self image", which is how we think about ourselves, and how we think others think about us. Some parts of this self image might be accurate, other parts might be less so. Bullying is the sort of thing that tends to make you feel there's something wrong with you, and your self image can develop parts to it that are unreasonably negative.
skyfall95, I'm assuming the troubling thoughts you're having just keep popping into your head, and that makes you feel upset? They call these kind of things "intrusive thoughts", and they're actually really common, they just don't become a big problem for most people. These thoughts are very well known by therapists, and it's very much the sort of thing they know how to help with. I only really learnt about them from a 2 minute chat during an assessment I had, so I'm not the expert. But I think the idea is that you can learn to just accept these thoughts. When you have them and try to force them to go away, it means that you stay anxious about them and they are more likely to pop up again later. Does that make sense?
I think understanding what's happening is the key to making things better. You might also find medications useful, possibly - if the problem is like what I described, then reducing anxiety will help to break that cycle. You're not crazy
Hope that makes some sense to you