I'm not making excuses for my boyfriend but
In the nicest possible way, you are making excuses for him.
this episode was the only time he got really angry and was swearing/screaming at me usually he is gentle and not a bad guy
Emotionally abusive men will work in cycles to try and keep you sweet and to keep you doubting yourself. If he was screaming at you all the time, you wouldn't be there. You said earlier that your boyfriend 'became a monster' when you didn't want to have an abortion. Would someone who is 'not a bad guy' do this?
I do recognise his short-comings in terms of his selfishness and immature behaviour and how he treated me at that delicate time and the unfortunate outcome largely because of it. He is the kind of guy who gets hammered on a night out and loses his phone/ or forgets to phone/ loses wallet
What makes you think parenthood will change this? Is this really the sort of man you want to be a father to your children? Or that you want your children to be like?
I've been just been in 2 other long-term relationships in my life and in hindsight those were bad choice in men. I guess in part I fell for current boyf because he was the nicest of the lot.
Best of a bad lot isn't a very good reason to stay though, and I think you know that yourself. Have you considered counselling of some sort? From what you've said it sounds like you've been in a couple of bad relationships and there might be bigger issues at play here. You sound as if you're very frightened of being alone, as opposed to being without him.
You deserve so much better than this. You say you're scared that other men won't have his good qualities, but while you're stuck with him you rule out any possibility of finding anyone who has better ones. Please consider contacting women's aid for a chat and saying to them what you've said here. Things can be better than this for you 