Smart parents not wanting to get stuck with a student loan or co-signing on a loan.
because rent is so high
Are you able to live with your parents? Is there anyway to reduce the cost of rent like renting a room? Can you move somewhere where the rent is cheaper?
working 25 hours per week
Working 25 hours per week and taking 6 hours is a pretty light schedule. It is not even 40 hours per week. What is stopping you from working 40 hours and paying for school from your salary?
In my own life I created a pretty crappy situation for myself when I was a young man. I really wanted to go to a prestigious university, but ended up going to a community college, and then to a university that was lesser known in a less expensive area. I had to work like crazy, upwards of 50 hours per week. I also took a full load in a difficult degree program.
You probably don't have to go to the extremes that I went through, but you can work more. Most adults work at their jobs well more than 40 hours per week, then come home and continue to work (on the house, raising kids, trying to start a side business, etc...). So you might as well become an adult now.
There are ways to become independent from your parents for FAFSA like have a baby, get married, or join the military. I'd only recommend the last one as you will also receive the GI Bill. Another option is to try and obtain a job that offers financial aid.