Substance Abuse Struggles | Being Honest with my Boss

I am a Manager in Corporate Development for a Financial Services- tech platform.

I am a Triple A rated addict who has a history of long sobriety, life management and a successful career.

I am reaching out about how to handle substance abuse disorder conversations in the work place. I took leave from work in May because I couldn't get out of a relapse cycle that was just crushing me. It was affecting my job in a serious way. I was either 1.) over medicated and what felt like barely on this planet or 2.) I was either constantly over substances or withdrawing heavily off of multiple addictive substances that they gave me to detox. 

I was honest with my boss about the first cycle that they gave me in the hospital and told him I had been sober for a long time, live in sober living and I couldn't go back to my house until I had finished my medication taper.

I took leave in May and I was out for ~2months under my ADA protection status (I was cleared to return to work after ~30days, but my company gave me a start date at the end of the requested period based on schedules). I had been sober for a long time leading up to this and was really proud of the progress I had made. I think my boss understood what was going on based on the feedback I got from him and through HR. I didn't have any citations for poor work performance, or being incoherent on the job. However, I was honest upfront about my previous substance abuse issues and why I chose a non-standard living environment for myself.

My job doesn't know what ADA (American Disabilities Act) protection I fall under, as I am protected from that being shared with my job. However, I was really really struggling, my brain was a mess from all the medications they gave me and I was literally going insane even when I was completely sober for months at a time. For those of you who don't know, the mental process of coming substances can be as bad the physical symptoms. It took me about 30days to come off of benzos, barbiturates' and alcohol in addition to attending a substance abuse program.
I was hoping to gauge the feedback from this community on just being honest and up front. I think it would go a long ways to address the leave, build trust and show that I have some humility. I would love some feedback from people here. I have a lot of anxiety and shame about the issue and I know how to get it under control. However, feeling like I am not being 100% honest with my boss is killing. I also think he knows what was going on. I return to work next week and I have been thinking about this for about a month straight.

In the past when I have been honest with managers it has actually gone a lot better than I would have expected. My company was in full support of me getting better and returning to work.