Dealing with Epilepsy and Anxiety: Need Advice on Non-SSRI Meds

I have epilepsy and bipolar. Recently my keppra was upped to 1000mg, and while I only started it Friday night, I’m still feeling generally very weak. I started a new very rigorous school program and I am always extremely stressed to the point of feeling auras and weak physically in general almost every day this week. I am extremely sensitive to serotonin, as Prozac and abilify together is what expressed my epilepsy gene (I did not have epilepsy before these medications) and I have had serotonin syndrome before. I need to have less anxiety so I will not constantly feel like im going to seize, but I’m sure my doctor will want to put me on an SSRI, which I am not comfortable with anymore. Are there any non SSRI meds that help with stress/anxiety? Did they make you gain a lot of weight? I also have trouble sleeping.