Since you don't specify even what country you live in, I can only guess that you are talking about some community college in the US. If so, then you are NOT being discriminated against--this kind of thng is simply par for the course. (You tend to get what you pay for, and CCs are not expensive, is the bottom line.)
Alternatives: 1) find some "backdoor" way to get the course you want. In my personal case, the only way to do so was to, illegally, work 2 full-time days for the admissions/registration dept at a CC before registration. In return, I was permitted to sign up for the classes I needed before "ordinary" students were able to do so. I don't know what similar kinds of deals might be available to you, but going in with a chip on your shoulder will NOT help you find them.
2) After all the prereqs had been completed, I went to a private, and very expensive, school on a fast-track program and was $43K in debt at the end. Are you willing to go equally far into debt?
So, my suggestion: rethink your goal and decide whether you are willing to do whatever it takes to reach it. If so, "affording" has little meaning, since loans, grants, work-study, scholarships, fellowships, even borrowing from one's family members, etc. are all possible.
If you ultimately decide to go to school, then be prepared for a LOT of these kinds of "games."
1) School is NOT a buyer's market, and
2) nursing schools are used to applicants who can be, and are willing to be, pushed around and who do exactly what they are told, when they are told to do it. If you don't fit that mold, then you can expect continued conflicts of this type.