Any advice? REALLY need help

My boyfriend of a year constantly talks to his friend who is a girl and likes pretty much everything she posts and he has admitted to me he used to like her. I'm not going to make him stop talking to her because I'm not that kind of gf but every time I see a message from her on his phone it kind of hurts a little. we've talked about it before and he has said sorry and I said I just wanted to lett him know but that I'm not going to make him stop talking to her because it would make me feel awful and I don't want to create any distrust in the relationship. I keep having dreams where he dumps me and I have trust issues because of family members and a past bf and friends but I know he's different and don't take it out on him but the fear will always be there. what do I do?


when I get upset I'm.not great at communicating using my voice so I wrote this for him. Do you guys think this is fair and worded right?

'I know we've talked about this before but it really bothers me you talking to Rachel. It makes me feel like I'm a third wheel to your friendship when you are texting her or when you tell her about things we have done that was meant to be memories just for you and me. Every time I see a message from her on your phone it hurts me because it makes me feel like she is just as important to you as I am and I'm not saying she shouldn't be important to you but I'm your girlfriend. Its gotten to the point that even if I see you like one of her posts or her name it hurts. It's meant to be just you and me in this relationship. You know I trust you more than anyone I ever have and I know you'd never cheat but I shouldn't have to have the worry right at the back of my mind because you text all the time and put kisses at the end when you only do that with me. If I were to constantly message a male friend and put kisses at just the end of yours and his messages and like all of his posts how would you feel? I'm not trying to make you feel bad or like you can't talk to her anymore but we need to find a compromise. '