I think everyone in this situation is behaving incredibly immaturely for their ages.
I'm not going to judge you for your reactions, but surely a surprise pregnancy is something you know is a risk at if you have sex - protected or not.
You would have had some idea of what would make sense to your relationship.
His actions and comments are very emotionally hurtful but you've only been together for 7 months - would you really expect him to guarantee that he would stay with you if you kept the pregnancy?
Then when he wouldn't (but did in fairness offer you financial support), you screamed and shouted and cried - which was your reaction to the stress of him not doing that.
It must have seemed like a massive temper tantrum to someone as emotionally stunted as he seems to be.
Take the lesson from this, it was never going to work. You were two completely different people and although you managed to convince yourself otherwise, he realised this and has rightly ended it.
No not in the right way and with no care to you, but 'logically' the relationship was over for him
The reason you're still upset is because you think if you had just been calm, you would have stayed together.
But you can't pretend to be someone else, just to keep a man. He is a detached person and you are not. At some point, this issue would have come to ahea. He would have always felt the same way if you displayed anything that wasn't perfectly calm.
I can guarantee that this has happened lots of the last seven months. You've gotten upset and he's gotten cold, you've aplogised and he's just taken your apology. Hence his comments about 'hanging on by a thread'. People don't flip like this, it should be a massive red flag to you that you both had drastically views of your relationship.
Some realisation was obviously happening in his head that you didn't notice and he didn't/couldn't/express until this situation happened.
Ultimately this about you not him, he has moved on. That's why he text you, so you know pointblank its done and you can't wheedle him back.
Him saying you have mental health problems is completely out of line but when you're recovered, you could probably do with some counselling to find out why you made the choices you did.
When you have a miscarriage, they may be able to offer you some free counselling or emotional support. If you use it, I hope it helps.