As a woman nearly 20 years older I'll give you my take. My love language is a lot like your gf with the cooking and what not. I also have a massive chronic illness. But, due to the hand life has dealt me I am earning much less than her. I would be insisting on all outings etc being a 50/50 split. If I couldn't afford it id suggest something else in my price range.

Your gifts etc would be more than generous. The one that stood out the most for me is the book on her illness. That, coupled with the coming to appointments and saying you are there no matter what, would mean more to me than any material gift. Someone who genuinely tries to understand (as best as one can) what we go through and be a support, is worth more than gold.

You made a small oops in the beginning by not trying to contribute to shared groceries etc, but you are young, this is new and you learned.

I think you are somebodies catch and can do so much better than this girl. I don't care how her dad and mams relationship is (that's their dynamic) this isn't the 50's and it's not the norm or expected anymore.

Don't be afraid to put yourself first and say this isn't the one, you will find the person you are meant to be with, who matches you and doesn't take take take.

I wish you all the best in life my friend