I assume that you live in a state that did not expand Medicaid coverage, and you're in the so-called "Medicaid gap"? In that case, this is the answer from healthcare.gov:
You can get care at a nearby community health center. The health care law has expanded funding to community health centers, which provide primary care for millions of Americans. These centers provide services on a sliding scale based on your income.
You also state that you have a job and that your income is not constant, which is causing your trouble on applications. A couple of points on that:
- If you work sufficient number of hours, your employer is obliged to provide healthcare coverage at a "reasonable" (as defined by the law) cost.
- You stated trouble completing forms requiring income because of the fluctuations that you experience. Usually some type of averaged value is appropriate to report in these cases. I definitely would not let that hold your back from applying for anything. It's not that unusual to have an income that varies throughout the year in a wide range of occupations from waiter, to farmer, to lawyer, to small business owner.
To the extent that you are blocked (legally or practically) from getting coverage, you will also want to take note of this, from the same page linked above, to avoid paying a penalty on top of not having coverage:
[If you don’t qualify for either Medicaid or Marketplace savings:] If you don’t have any coverage, you don’t have to pay the fee. Under the law, most people must have health coverage or pay a fee. But you won’t have to pay this fee if you live in a state that hasn’t expanded Medicaid and you would have qualified if it had. This is called having an exemption from the fee. You can get an exemption when you apply for coverage in the Marketplace. Or you can apply for the exemption without having to fill out a Marketplace application.