I agree with BigLucy. Do not let this evil person dismiss you. If you are in a state school, you have rights, you just need to find the path that will get them for you. Although for different reasons I have had to fight for my daughters rights at every step and I have dealt with many idiots like the person you dealt with.
Please start on campus. It is just easier to find an advocate inside the system. These things just work smoother when you find a friend inside. Once you find one, take care of that person. Small gifts, thank you notes, ....
However, if you can not find someone in the system, then look for someone outside. Most ADA lawyers will see you once and can provide some advice. They might even take your case for free. Most likely all they would have to do is write a letter threatening to sue. Also, you might even think about going to the campus press, they might support you.
This is not fair treatment and I hope you find a path that gives you what you should have
Dave