I would prepare yourself for a long difficult road. I envision several RFE's and quite possibly an outright denial. Do your legwork upfront. Get the taxes straight and joint assets created to show the bona fide relationship.
Based on your income level, I agree with others that you should go to a community college and work towards a degree or trade certificate. At your income levels you would be eligible for pell grants and other financial aid that would most likely not require paying back. Even if you have to take out a student loan, you don't have to start paying it back until after 6 months from graduation and you could work out other arrangements to minimize the financial impact of the loans up front and a 2 year degree at a cc would probably only result in couple thousand dollar loan that can be paid back over many years resulting in an extremely small monthly payment. I paid $400 per month on over $90k of student loans. A $5-6k loan (probably far less than that with grants and so forth) for a trade certificate or associates degree would be very manageable when you got a higher paying job.