now he's lying to me about doing shrooms. not that i CARE whether or not he does them (i do a little but i wouldnt try and stop him if he told me he wanted to do them) ... i just care that he has lied to me MULTIPLE times about it.

All this makes me wonder what else he has lied to me about in the past, and what he might lie to me about in the future.

I love him SO much, but I can't be with somebody who I can't trust. I dont know what to do... Break up is what all of you would tell me to do, but i just feel like there's got to be SOMETHING else i could do to fix all this.. but i just dont know what it is.

If you don't have trust you have NO relationship.

I think its time to look him in the eyes and tell him directly what you are thinking and give him an ultimatum to either stop lying or its time to move on.  I wouldn't put another minute into him if I didn't trust him.  You are wasting your time if you do and only delaying the decision to deal with it.  Do it now or later but time is very important.