How can I support my mom? She's confusing me right and left..?

He may be contributing to the problem but your mother is responsible for her own feelings and behavior... if she is that depressed she needs to go to a doctor and get it dealt with and not just sit back and blame everythign on your stepdad..... He is what he is and will nto likely change so your mom needs to deal with her own issues... if it is that bad then she should leave but again she is the one who needs to take action.