I've been umming and ahhing for hours over whether I should post this and I'm still not sure it's completely the right thing to do but I've read this thread and the other thread about the 2.1 and well, here goes.
From what you have said on these 2 posts (and I realise it's only a fraction of the story) your dp is the worst kind of controlling, manipulative man and you will hopefully come to realise that you have had a lucky escape.
From an outsider's POV, he appears to be gradually pushing you into seeing yourself as a bad person - .."you had the opportunity, the time, the talent to get a first more than anyone else on the course but you didn't have the discipline. You may as well have done it when you were 21. You can never go back and change that result now.." I'm sorry, you've gone from no academic qualifications to getting a 2:1 degree with a baby around and it's not good enough for him. That's despicable behaviour on his part.
To me, it's coming across as the beginnings of domestic abuse. He's undermining what you've done, he's telling you you're not good enough, everything is your fault and there is a part of you that's accepting it. 'I made him so angry that for a moment he was afraid he was going to loose control and he say's he can't come back from that, that he can't be with someone who has the capacity to make him so angry'. This isn't your fault AT ALL. He's totally let you down whichever way you look at it, he's unsupportive, negates a fantastic achievement you've made, so where will it stop? What happens if the next time you have a row he does lose control? Will it be your fault he's hit you, you drove him to it?
'I couldn't forgive him for his reaction to the 2/1, that he only focused on a thearetical loss instead of rallying and getting on with it. I couldn't let him turn such an event into a shameful episode to be regretted forever more, even if I was dissapointed myself.' If it wasn't for everyone on mumsnet, how would you be feeling about your degree? Would you be so determined not to let him belittle an amazing achievement if you hadn't had so many people supporting you? You are absolutely right not to forgive him, it is unforgiveable.
I'm sorry if this is all way out of order, but I'm just saying what is coming across to me. I think you will be far better off without him and the sooner you can get away with some of your self esteem and self confidence intact the better.