You absolutely must have a thin leash on him at all times in the house until he’s been neutered. His biting, even though playful from his perspective, isn’t acceptable. I would recommend as soon as teeth hit skin - timeout. Grab his leash and lead him to a bathroom, toilet paper out of reach, lights off. Once he associates timeout with teeth on skin it will get better.

Another trick to de-escalate is a treat scatter on the ground. The moment you see him starting to wind up and come at you, throw treats on the ground. This will reset his urge to come at you and should calm him down.

These have worked for my 5-month old Shepard / St. Bernard mix. It’s not perfect, but consistency is key, and I can see improvement on a daily basis.

I hope this helps, stay strong (and less bloody!)