OP, I commented on your thread at the beginning but it appears I didn\t see your updates. I'm always a bit hesitant to tell this story becuase I think it can give false hope to women in truly awful, abusive relationships. But I'm going to.
DH had a temper. It came out a few times when we were first together. Not just to me actually - I saw it in other scenarios too and a few friends/family had mentioned it. And quite often these temper tantrums were clearly just him having a meltdown because he didn't get his way or people didn't agree with him. I had even lost MY temper (but not in a DH way) with his mother on one occassion when he was being a complete dick and she told me to let it go because otherwise he'll carry on (spoiler - yes, his upbringing has a lot to do with his temper and inability to control it).
In the months before we got married, there were two big incidents in particular. One didn't involve me. The second did. On that occassion, he was so angry about something SO stupid. Like your DH, he ws driving and he nearly hit a cyclist as he screamed at me and hit the steering wheel. When we got home, I was distraught and left the house. Over text, I told him to go stay at his sister. He was, at first, still angry. Accused me of doing all kinds of things and making a mountain out of a mole hill and also that the original argument was all my fault. I think that's what made me able to be so 100% certain that HE was the problem - the original argument was because I'd asked him to turn off a radio station playing music and talking in a language he grew up with. He took offense and claimed this was me "disrespecting his culture". Obviously, that was total bollocks.
I was just sad because I knew I was going to have to cancel the wedding. When he calmed down, after a day or two, he apologised. Told me that he realised he was wrong etc etc. But threw in the "I just can't help it and I'm sorry" bullshit.
I told him that if he didn't seek help, immediately, I would be cancelling the wedding. That no way was I bringing up children in this sort of environment and I wasn't going to put up with it any more. And I meant it.
And to his credit, he did. He started therapy that week. And he did the work. it wasn't easy and there were ups and downs. And in fact, after about a year, he stopped therapy as we thought things were fine, but a year or two later I started seeing the signs. Again, to his credit, he went back to therapy and actually, i think this time he PROPERLY dealt with the issues. And while he still has a bit of a temper and can be a bit moody, we've never had that fear and trauma again, and we don't walk on eggshells.
So when I see this in your post:
I did try and talk to him a few days ago about going to a GP/counsellor and he got really angry with me. Said I was tense and that made him depressed. Said that I was ‘gaslighting’ him which upset me because I’m not and I feel I do so much to support him. i tried to tell him how hard it’s been for me but he got really upset and said I was ‘making him feel shit about himself’.
All I could think was how differently MY DH behaved in a similar situation...... When calm, my DH didn't try to blame me. He didn't claim it was depression. And HE accepted that HE had to do the work to fix himself.
If your Dh can't do that, then I think you have a bigger problem.