In need for major breakup advice

My bf and I have been together for six months. The thing is he is very hot and cold. We’re fine for a few days and then something happens and then we argue. It’s like a circle. I feel we both are stressed in the relationship and I feel te best thing to do is end it. I’ve never been in this situation, so I’m really freaking out. I’m so scared he’s gonna cry, be very upset, and I don’t want to hurt him. He always says how much he loves me and I’m so scared of how he will react. Being in this situation now, I feel he won’t want to find someone and that also makes me sad because it will break his heart. HELP!!!!!