I messed up, need advice on what to do

Back in October I committed to an ED program for a T10 and an REA admission plan for a HYPSM. I was accepted into the ED school and deferred from the HYPSM, but I now realize that I hate everything about the school I was admitted into. They have offered me a lot less financial aid than I initially thought I would receive, the location is awful, and I do not think that I will fit in with the student body. I have tried contacting their admissions office, but everybody is very unhelpful and I can not get into contact with anybody about the financial aid situation.

Meanwhile, I feel hopeful about the HYPSM that I was deferred by, having written an excellent LOCI with plenty of updates such as being announced as a semifinalist and winner of many prestigious scholarships since I submitted the application, and some achievements related to my top two EC's.

Having gotten less finaid from the ED school than expected, I kept my RD applications in and have gotten acceptances from some top EA schools, such as UVA and USC.

I guess I don't know what to do, and am looking for advice.