Weed is Ruining My Relationship

My fiancé and I have been together for three years. We used to smoke weed together quite often before we had our daughter. When I got pregnant I stopped and he kept going. It wasn’t a problem, but then I noticed he would smoke everyday. He used to even smoke before work. I asked him if anything was on his mind that he was trying to get away from and he said he just likes to be high. He would offer to watch our daughter while I went out for me time or to shower but I always have her to my mom bc I don’t like him watching her while he’s high. He argued and said he was completely aware but I still didn’t like that fact that he was high on drugs and watching her. I’m worried because we can’t even hang out without him having to get high first. He won’t compromise and slow down. He refuses.