Phew! You are a bright young woman- despite being hearing-impaired you write clearly and well. My first devices were analog and I hated them for all the same reasons you dislike yours. You can't pick individual voices out of the background noise to make sense of conversation. The aids are useful one-on-one in a quiet place and that is about it. I'm shocked your audiologist has not explained this clearly to your mother. The problems are technical, not emotional, and it was a very smart move to come on this forum and ask advice. Do you have any classes at school that would let you study the technical reasons hearing aids sometimes don't help?
(I think the system your teachers use is the hearing loop (http://www.hearingloop.org/)).
Your autoimmune disease puts a spin on your situation that complicates things for everyone. I imagine your mom has been deeply worried for you a long time and that the burden of health care costs on your family makes all of you quite nervous about expenses. Your move toward taking charge of this entire issue is going to be a big win for the whole family.
Finally, cuz sometimes I talk too much, check this thread about migraines and hearing;
Don't let is scare you since the 2 are linked for only some people, but do tell your autoimmune doc you think the devices bring on migraines sometimes. See what s/he says. I am not prone to migraines but sometimes I get headaches because the ear molds irritate me.
THIS IS A JOB FOR SCIENCE! oh wait, I said that already...