If they really like you, they won't care what you do.
If you are worried about not earning money, perhaps you could start some sort of online business? Make something to sell online (It only costs about $15-$20 to set up a website).. At least then you'll be able to say you're starting your own business and that might help give you some more confidence.
Just trust God... He will set you up with the right girl who is crazy about you and wants to be with you even if it's hard because you care for a family member. Anyway I think it's admirable to take care of someone and I'm sure there's women out there who feel the same. Every woman is different- you'll find someone that's right for you in time, just trust in God... His timing is perfect.