FWB... but feelings

I've been FWB with this guy since March. I've developed extremely strong feelings for him, but when we agreed to it at the beginning, we said no feelings, so I haven't told him. We've been getting in a lot of arguments recently and I've debated telling him how I feel, knowing he doesn't feel the same way, but I feel with the arguing, he'll stop talking to me. I'm stressed 😅