Doses of medications are different for different people, you need to work out what works for you, not based on what other people were on.

I was on 400mg of lamictal, I think that is a pretty normal dose for people with Bipolar, it doesnt start working until over 200mg anyway. Same with Seroquel, it doenst work as an antipsychotic til it is over 200mg.

I doubt my diagnosis from time to time (only when I am stable or up) but my support network and doctors remind me that it is correct and I need to stay medicated for now. These meds dont sound quite right for you, if your pdoc is not keen to change them, find another. There may be meds out there that dont give you annoying side effects. (although I suspect it is the seroquel giving you the side effects you dont like, lamictal may very well be enough but only you and your doctor know that.)