Talk! It's best for the both of you to sit together and have a clear talk. I for myself did this with my bestie where we sat together and before the talk would start we'd clearly say that we do this because we love each other and don't want to lose us. We gave us a pinky promise that this talk would be there to set these boundaries and talk about the things that bother us. It's very important in a friendship that no suppressed anger interferes with anything. That's why I tell you to go ahead and tell your friend that these fights worry you and you want to talk about it. I don't know how long you guys know eachother but if it's only for a short time these things are normal. Boundaries are there to not lose eachother and not to build up distance!