Well duhh, you've already proven that you don't deserve to be trusted.
It's kind of a double-edged sword. I mean, you shouldn't have been having conversations with a guy with you cheated with on your current boyfriend and he shouldn't have checked your FB account. However, I think that if I were in the same shoes and my boyfriend was still talking to the girl he cheated on me with... well, I think we wouldn't still be in a relationship.
It's all or nothing and I think you're getting off easy. You hurt your boyfriend once already and now you're hurting him all over again by continuing to communicate with this guy that you had sex with while you were still in a relationship with your current boyfriend. I'm sorry, but I think that in this case you're wrong.
What should have happened is... your boyfriend should have picked up that phone and had all his fears put to rest when he opened your FB mailbox and found no messages from any guy whom you might have sex with. Life would be much easier right now. As for the mean texts...you're going to have to deal with them.
He's hurting and rightfully so. If you want to keep him then just keep apologizing and get rid of the "back up boyfriend.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.