Significant other using drugs, I can't take it anymore

I'm in tears writing this ...the fact that the love of my life has an addiction problem is killing me. We're 7Mos pregnant, in the beginning he quit and told me he wouldn't do it again....now every other month I'm catching him doing it and its the same thing "babe I swear I'm going to stop right now" 😢 I can't even fight my tears any more ...i can always tell when he's using. He's up all night, he hardly notices im there, and hes very insensitive of me when in reality when hes sober hes always checking on me or cuddling me....I've lost faith in him completely.. I think to myself maybe he doesn't love us enough to stop.. or maybe I'm not loving him enough for him to stop. I'm so depressed.....I have no idea what to do. I want him to grow old with me but how's that going to happen if his heart gives out from using? I'm torn to pieces. Has anyone else experienced this?