Possible trigger?

So I think I may have just figured out a trigger for my depression! Because I don't have a lot of friends because of the bullying and me closing myself off to people, it gives me a lot of free time and time I spend  by myself. With my free time, It gives me a lot of time to think. What I think about though, is the past. I think about all the times people have hurt me, but instead of thinking about what I could have done differently to change things, I hold onto the hurt. I remember how people hurt me and why they did it. I realize that because I do that, it gets me down a lot. So in order to avoid thinking about the past, I imerse myself in video games, computer, sports and hanging out. I don't do a lot of other things because I'm worried I'll have time to think. I'm still kind of shocked that I figured this out. Could I be right about this???