Medicating for Mental Health During Pregnancy

Firstly I'm just curious, not getting pregnant anytime soon just planning ahead, I have never had to take myself off of prescriptions before for pregnancy, I was on a prescription that didn't affect pregnancy. The ones I'm currently taking though, are a different story, I take Venlafaxine for my major depression & anxiety, and I take Oxcarbazepine & Lamotrigine for my bipolar 2 and all give off red flags for pregnant people, so ig my question is, how would I medicate for my conditions during pregnancy? Obviously I can't take my prescriptions during the first 4 months, maybe even the whole pregnancy. So ig how do you treat your conditions during pregnancy without medication, because when I'm not medicated, it's REAL bad, like I'm talking auditory hallucinations, inability to stay awake, and constant crying for no reason while awake.