OP, I'm so sorry to read what you are having to go through at the moment. If you feel like you want a bit more time to think everything through, how would you feel about postponing your appointment slightly? If I read correctly, you can't have the type of procedure you'd hoped to as you'd already be too far along for it by the time they fit you in. In that sense, could you give it a little longer?
You are evidently a very kind and thoughtful person and, to be honest, I think you are wasted on your DP.
If you decide that you can't have this baby for the reasons you've mentioned, but this experience has made you realise you do want the chance to have a child, I'd ditch the DP and take steps to make that more likely! I agree with PPs that he's not going to change his mind on this matter, regardless of what he's saying now to try and keep you. In fact, based on what you've written I really think you might be much happier without him, child or not. I can imagine it is quite eye-opening to see what his reaction to your pregnancy has been, and perhaps you will feel you can't look at him the same way anymore.
It would clearly be exceptionally difficult for you to have the baby alone lack of nearby or family support, the issue of your commute, etc and you also say you had always decided you would not bring up a baby alone, based on your own experiences growing up. Just to say, don't feel you have to stick to a theoretical decision you made before. You are pregnant now, and say this may well be the only opportunity you will get to have a baby. If your previous thinking still holds true that's fine, but it's also ok to say, "I know I said I'd never do this, but now I'm in the situation I feel differently..." And if you were split up before the baby arrived, it wouldn't have had to deal with a break-up or be a child from a broken home in the same sense: its home would always have been with you. Or, supposing you did not break up now but did further down the line, you would be extra mindful of not making your child go through the same things you did (being party to parents' hatred of one another). There's a website and charity called "Gingerbread" which I found helpful for working through issues likely to come up as a single parent.
And ultimately there would be ways to make it work alone: for instance, you could quit your job after going on maternity leave, relocate to a cheaper city where there would be better job prospects without the commute but with affordable rent, go to university and retrain. Maternity Allowance/Pay and possibly Universal Credit would be enough to scrape by on. At least it would be something you might want to look into. Granted, it would be a matter of uprooting your entire life and expectations for the sake of this baby, but if you have decided you want this baby (or even that you just don't want to not have it) that's reason enough.
I left my (abusive) ex during my pregnancy, moved to the other side of the country soon after baby was born, quit job etc, and am so relieved I have kept the baby. For me, it's been harder than I could have imagined but worth it a thousand times over.
This isn't meaning to persuade you to keep the baby, though. Just to give yourself time to think, and suggesting that there might be workable ways to keep the baby if you feel overall that's what you'd rather do, and that if you can give yourself enough time to think first then I hope you'll feel more at peace in years to come that whichever decision you did make was the right one for you.