Living w/ SO problem?

My boyfriend and I have been together for five years now. We're about to move in together. I have very bad anxiety, and have issues going to the bathroom in public. I am EXTREMELY comfortable around him, don't get me wrong, but I've rarely ever used the bathroom at his place whenever I go over. Now that we're moving in together, I don't want to be like that anymore. Any advice? Tips? I realize by now I should be able to do this with no issue, but having anxiety ruins a lot of things for me unfortunately :-(