I don't know what to do?

Well Eric and I kinda got back together going slow so for now we are exclusive but in a couple months we are going to make it open that we ate bf/gf and have him meet my parents. I just hate I worry and know that he still every couple days go on pof. What do I do about that? Also we have been on and off a couple times for 2 years. He's 26 and I'm 20. I also have very bad anxiety.