First of all, the fact that you have to take resits doesn't mean that you ****ed up in your course. Bloody hell, I'm taking my exams in September and I'm nearly at the top of my class. It certainly applies that resits doesn't mean you're stupid or that you've been "swanning around".
If you think that this is what you want, by all means you should go for it. You've paid for a year's worth of tuition and you obviously want to carry on so do it!
It is absolutely your decision.
Why do your parents have such an agenda? I mean, do they get something from your changing course and working this part-time job? Whatever the reason or reward, it certainly is not for your sake (unless they think that you would be better suited to this other course).
And as for the financial situation... why do you need their money? I honestly don't get it. If you're in the boat as the rest of us (i.e. you get a grant and loan but have to pay accommodation and living expenses) then you don't need their money. If I am wrong, please say. There may be other ways around the situation.
Anyway, for your own sake, go and think about what you want to do. If you're absolutely sure that you're doing the right course, and that you're happy with it, and that you're capavle to passing it, then there is no other decision to be made.