Notalone, love, I congratulate you for getting out of an abusive relationship, I really do. I am going to be straight talking with you love. I hope you don't take offence.
I don't like the selfish comment either.
He has told you in a round-about way that his heart attack/angina is none of your business. You've known him 6m. He kind of has a point.
May I remind you that ALL abusers can sustain the appearance of being wonderful WAY past 6m. You are calling him your DP. He's not. he's a BOYFRIEND.
From here you appear to be WAY too involved in his health. I understand your concerns, but tbh, he's got a very dim view of his life at the moment, and perhaps with good reason, you don't know and are not likely to know either. BF's not going to discuss it.
You are doing that thing of Hanging on in the sidelines, that being supportive and Being There For Him. You are getting caring mixed up with love tbh, be on your guard. You are giving him a title and position/stature in your life when he has done nothing to earn it. Riding in on a White Horse to save you from an abusive relationship is actually a red flag all by itself, so if that's the case, we'll need to start a tally...
Don't take the opinions of others into account when judging a person! ALL of my X's friends/acquaintances will tell you how wonderful he is, I would have told you how wonderful and supportive he was in the first 6-12 months.
You are focussing ALL your attention on this man, you are discussing/considering children with him when you don't even know what he's like with your own (good move for not introducing him yet though!)
If he is saying he doesn't want more kids, and you think you might, then why are you even contemplating sticking with this? Why do you not deserve the chance for a new full life? He needs to know that if he is going to curtail his own life (and yours by default) that perhaps he needs to understand that you have other options, that he is not going to reduce your future. And certainly if he's not even going to involve you in his life.
My feeling is that this is all too fast, WAT too fast. You don't know this man, you need to really back right off and see if this man really IS the bees knees you think he is. I can guarantee he's not. No-one is.
This SELFISH comment should be your Red Flag. 6m is usually where they start appearing, but very very subtly.
Be wary, open your eyes and really look at this, what is in this relationship for you. If you are young enough to have more children, why stick with someone who denies you that, for his OWN selfish reasons?