It's understandable that she doesn't want to support you forever. You are an adult, and at some point you become responsible for supporting yourself. She could - and should - have expressed herself better, but perhaps she was just feeling frustrated.
I think you have to face the fact that at some point you must either accept adult responsibilities, or take the other route. The choice is yours. You won't be able to put off that choice forever, and judging from how your mother seems to be feeling you may not be able to put it off much longer.
I have already suggested what I think is your best way forward. Get out into the world for a year or so, and see how it goes. If it's a success, that's great. If it's a disaster, you can choose to ctb at the end of it, knowing that you tried your best to make life succeed.