Terrible 2s and how to deal

My son is 2 and he is going through that awful stage right now. He is my first child so I've never been through this before. My daughter is 1 and he is so mean to her. He will push her down for no reason, hits her, etc. My husband tries to convince me to spank him so I've done that and it does nothing..he still does the same stuff and actually spanks me when he gets mad at me. I've seen him hit his sister's bottom too when he gets mad at her like she's in trouble and I definately dont want that. I try time out as well and it seems to have a little more of an effect because he is loving and wants me to hold him when he comes out but the only place I use to time out is his room with a gate up and I dont want him to view his bedroom as a place of punishment. Any tips or ideas? He has a lot of anger and also throws toys or anything he can get his hands on at me when he gets upset. I just want to get this under control as quick as possible and I feel stuck.