Husband keeps saying our son is just being a boy

I have one son and two daughters. We've had some issues with our son. I think he has bad anger issues but my husband just says he's just being a boy. He's 15 and he's punched holes in our wall and we've had to pay for him putting a hole in the schools wall. When he gets mad he either hits a wall or hits himself or starts banging his head in the wall. He will pull at his own hair when angry. Last year they wanted him to see the school psychologist because some girl made him mad. They were playing volleyball in gym and she spiked it and it hit him in the face by accident so he got mad and started slamming his head into the wall and busted his own mouth. My husband kept saying he doesn't need to see the school psychologist and that boys gave rage and he's just getting it out. My husband thinks as long as he's not hitting other people he's fine. He was arguing with his sisters yesterday and went and punched a hole in the way and started hitting his head on the wall. I told him to stop and tried to get him to. He pushed me off and went outside and started hitting his head on the tree and would not stop until he made himself pass out. It scared me. I took him to the hospital and now he has a concussion. The doctors said we need to take him to a psychologist and my husband argued with the doctor and said "Boys have rage. Boys will be boys." My husband said he's not hurting or hitting anyone and the doctor told us that him hurting himself isn't any better and self harm is self harm whether it's from depression or anger. My husband believes our son is fine and probably learned his lesson and won't do it again. I think we should take him to see a child psychologist because that's some of the worst it's gotten. Before I could at least get him to stop slamming his head and this time he kept doing it