You're both doing the right things. Well done 
I hope the GP sees the seriousness and does an urgent referral rather than attempting to manage it themselves (otherwise known as faffing around in my book!). I think they will see the potential risks though, as shocking / rare as they are.
Baby on the way should be the decider if any hint of faffing, though I've hesitated about writing that as it could be seen as trivializing the danger to you, which I feel is very very real.
Am amazed to find out that others have stories/ experiences of strangling. I thought it was rarer. It's nice (in a not nice way) not to be alone.
My STBXH strangled me in his sleep, maybe three or four times. I didn't take it seriously enough when it happened, and I look back with utter horror at the way I just failed to react to a very real danger of death.
Necks are so very very vulnerable. They really are. A death squeeze/ blow/ hold is such a small amount of movement away, it's a big of a design flaw really, but they need to be treated with respect and care.
The last time was worse than hands round my neck (I know, like that's a sentence that should ever be written). He got me in a head lock with one arm, round the neck, but this time he got his other hand under my chin/ side of face and jerked my head sideways... You know, to break my neck. Or rather the neck of an armed soldier coming at him when he was cornered, unarmed and fighting for his life (as a teenager trapped in a war running from conflict and doing anything not to be forced into fighting). So yeah, traumatizing for him, and obviously he needed help with his PTSD. An awful lot of help. But not from me, from professionals. And before he kills someone, not after. Love really does Not conquer all.
I know how close I came to death, a couple of millimeters away in fact. I told a doctor in passing, and saw their reaction. I think I always did know really underneath.
I'm so glad your dh is reacting differently, with love for you. Mine chose to dismiss the whole thing as he was embarrassed that he was 'mental' and didn't want to tell anyone. Looking back... What the actual hell?! He'd rather risk killing his wife than see a gp? Nice.
Anyway, you're in a different situation, phew! But really, I don't think you can react too much in this situation. You can still love and adore him, and he you. But it needs sorting, and as he loves you lots he needs to protect you at the moment, and you are thinking of him, as well as you, in getting it sorted, as you would want to protect him from the terrible circumstances in that link. Imagine the guilt and horror of knowing you had killed your true love and mother to your children. Shudder.
On the up side it sounds like it could be sorted by low dose medications so that's really hopeful.
Good luck to both of you, it must be really hard.