Trying not to control boyfriend’s behavior or let his behavior affect me

I know we have to let adults be adults and can’t control other people, so I’m seeking some guidance in working through this.

One of the reasons my BF and I had broken up a few months ago was because he was smoking pot about 99% of the time we were together. I never cared that he did it but cared that he was doing it so often. He decided to stop on his own and in March had called me to tell me he had not drank in a month (the bigger issue – when he drank hard liquor he got mean sometimes). And that he wanted to stop pot for awhile but he may go back to both – he just wanted to be able to work on his sleep issues first and that if he were to go back, he wouldn’t do it as much.

He still has not touched a drink but 2 nights ago did pot again for the first time in 2 months. He also has a long way to go with his sleep issues and is not wearing his sleep apnea mask consistently like the doctor recommended.

I love this man and can see myself being with him forever but as we discussed, he’s not going to be doing pot often when he has kids and it would be very difficult for him to have kids with his sleep at what it’s at now.

When he first did the pot again I had multiple thoughts:
1. I’m having bad memories of him being high all the time in the past.
2. He’s going to sink back in his old ways and I’m not going to be able to be with him which would suck because I love him and want to be with him.
3. He’s an adult – I can’t control him.
4. I need to remain calm and not let emotions get the best of me.
5. I have not touched pot since he stopped to support him and enjoy it from time to time so now we will get to have some fun together.
6. But, If I never touched the pot again in my life I wouldn’t care. The same does not go for him.

I don’t want my feelings about the past to get in the way of our present. I want to continue to just enjoy the moment with him and see how it goes.

This morning I’m in his bed and he’s out on the couch sleeping – something he has done in the past when he can’t sleep. He goes in there to watch TV and not wake me up and I’m annoyed and worried because he did not wear his sleep mask last night.

So how can I process all of this and be in the now? I want to just see how the future goes and if he reverts back to past bad behaviors then I obviously will have to leave him. But, what if he’s not going to and is able to cut back? Then I could stay.