Guy issues

Me and this guy I've been talking to got into an argument last week and ever since then nothing has been the same. We can't seem to hold a convo. And I don't know what to do. I don't wanna give up on it. The last thing he said to me was "ok" and now I don't k ow what to say. What do you do when you lost a convo but don't wanna stop talking to them?