I need bf advice

I love my boyfriend to death. He has really bad anxiety and is constantly thinking the worse. I also have anxiety but not as bad so I sorta know how he feels. It is an everyday occurrence of him asking if i’m talking to anyone else or if i am cheating or still want to be with him. He cries pretty much everyday. Just last night he cried because we were on ft and I seemed happy but I was happy because I was talking to him which I explained to him. It just seems as if he doesn’t trust me and is always miserable. I honestly don’t know what to do, I always reassure him and tell him how much I love him and how much i want to be with him but it just seems like its never enough.

Any help, or advice, or anything is greatly appreciated