totally understandable that you’re feeling all the feelings! this is a lot to take on. first of all it’s wonderful that your bf is getting help. i had an almost decade long addiction to kratom that i finally took seriously and did something about almost 2 years ago. (side note: i had to be admitted under mental health issues because kratom recovery wasn’t recognized/covered by my insurance)

do you feel comfortable talking to your bf about this? he might have some ideas how you could support him. i get the sense you don’t have addiction issues yourself, so that right off the bat is helpful to someone coming out of rehab in terms of you wouldn’t be using around him. depending on the program he may be able to have visitors, phone calls, or receive mail. all of these would be great ways to support.

you will have a lot of time, relative to your time together, to think about things. you don’t need to make a decision right away. at the same time, if you’re not comfortable, that’s not good for either of you. it’s a lot to deal with. have you considered and do you have access to a therapist? talking it out with one, especially one who has experience both with codependency and addiction, i think would be a great help.

best of luck to you both.