I am concerned that the environment at your current school is truly destructive for you. We can debate whether or not your perceptions are supported by reality (I trust you actually) but it is your perceptions and feelings that count.
You seem to have a lot of support at the school. However, I am not sure you can overcome the unhappiness you are feeling and I am concerned for your well-being. Antidepressants can be really helpful and make therapy more effective, but you do not want to take them. (Often you have to try a few before finding one that works and doesn’t cause side effects.)
There are other options besides USC. Many schools will let you take classes as an unmatriculated student and there are continuing ed programs at most universities. Perhaps you should consider moving home to a more urban (and warmer!) environment and taking classes while you apply to other schools. Granted, they would have to be affordable and you have substantial aid where you are.
I just don’t want you to feel trapped. Knowing that you CAN leave and the world won’t end, might even help you stay. Please please know that your well-being and safety are the most important priority no matter what.