I am very sorry to learn about this situation.
Unfortunately the lease that you signed is going to be enforceable.
Being under the influence of any substance (alcohol, narcotics - prescription or not, or having a mental disability) does not automatically void a contract that you enter into.
The only time that this occurs is when the other party is aware that you are under the influence, and either knows, or reasonably should have known, that you could not comprehend the terms of the agreement that you were signing. (So it requires both knowing that the other person was not at full capacity, and that this capacity altered their ability to understand the contract).
In your case, it appears that you signed a lease contract remotely (electronically) and the other party (student housing) was not even present at the time that you did so. This exception would not apply.
You can try to mediate the agreement with them - contact the local bar association and ask for referrals to mediators, or contact the university resource center for referrals from campus, but as a default you are going to be responsible for the terms of the contract that you agreed to.
I do wish I had a different answer for you, but I want to provide you with a clear and concise statement of the law so that you can proceed accordingly.