Hi and welcome Iris
None of us can tell you what to do but I think ti's good for anyone in your position to think about how you'd cope with years of this kind of 'come here go away' 'will today be good or bad' uncertainty.
It's absolutely not up to you whether your bf stays sober and clean or not, and you're not to blame in any way if he doesn't.
Think about yourself in all of this - think about what you want your life to be like and go from there
you are very welcome to post here - do check out our family and friends forums too
https://www.soberrecovery.com/forums/#friends-family
D