giving up alcohol and getting sober from a person

My boyfriend last night was found to be in a guilty cheating sittuatuon he has never cheated on me (that I know of) in 3 years. Our relationship tends to get emotionally abusive but that's just us.
But I draw a line I refuse to let this relationship be like my last in the sense I stayed while I watched a man cheat on me.
So I want to give up alcohol (I think it will help me lose weight)
And I want to give up my boyfriend but I'm honestly a little addicted I always want to text back
So I am asking for advice on getting through the first 30 days of no alcohol
And the first 30 days with out texting or calling my ex