I'm not blaming the OP, @KierEagan at all - your post is really aggressive, so maybe you should take your own advice about self-reflection and considering your own insecurities?
I'm sympathetic about @hoopoemagic 's situation, which is why I think girls and young women need some guidance about not getting carried away by "romance" - I know I was, although luckily not financially. It's good to trust those whom we love but I think that sometimes girls & women are socialised into the "love at all costs" and somehow think it's wrong to look after themselves financially. And men benefit from that, as in the OP's case.
She's been screwed by a man whose taken advantage of her, and her parents are being overly cautious in ways that perhaps they haven't thought through in terms of looking out for their daughter & grandchild.
But back to @hoopoemagic 's dilemma - could you talk to your parents OP, about what is going to be possible for you in terns of renting or buying in your area. Can they be gently persuaded to see that not helping you will result in you having to live in a "rough" area anyway? And with a much lower standard of living because a private rental is far less secure.
Are you tied to the place you're currently living in? My home town is in north Lancs, and there are more and less desirable areas, but the so-called "less" desirable areas are actually places where there are lots of families and facilities for them. There are some really nice houses in those "less desirable" areas. It's just that the people living there are not particularly middle class. But they're totally respectable & family-oriented.
It sounds to me as though you're also nervous about talking to your parents honestly. Do you have siblings you could discuss this with? Ideas about how to approach your parents?
I remember the 15% interest rates & negative equities of the 1990s - I'd just bought my first very basic tiny house (with no heating etc). But I suspect that we won't see those sorts on interest rates again - the political fall out would be too much, because of what happened in the 90s. Good luck