My (31f) bf (31m) was great until he got addicted to 7-OH?

We’ve been talking 8-9 months and had a kinda steady but slow progression to a relationship. He really wanted a relationship but l wasn’t ready since I had just came out of a 6 year engagement. We finally started dating about 3-4 months ago. Everything was great and I really felt so lucky and happy until one month into us dating.
We both started taking 7-OH (like a very intense kratom..pretty much opioid) and that’s when things started changing. We were both hyped for awhile on this drug, it gives you so much energy and things are more fun and the pain relief is amazing. Well, he got terribly addicted to it, taking wayyy more than the average dose.
It started to make him irritable, less loving, no libido, just in his own little world. It started making me more emotional and with him acting distant it was just a bad combination.
Fast forward like 2 months and he’s finally decided he is in fact addicted and needs to get off of it. He is able to successfully wean himself off and then stop completely.
But ever since things haven’t been the same like how they once were before this drug. It’s been 2 weeks I think since he’s officially been off of it. I’m so worried it will never be the same again. I need that loving affectionate man that I once had. He was so nice and patient and thoughtful.
Just wondering if anyone has experience with something like this? Will he get back to the way he was or are we screwed?

TL;DR— my boyfriend got addicted to a drug and has since stopped it 2 weeks ago. He used to be wonderful and sweet and loving and now he’s pretty much none of those things. How long does it take after addiction to get back to your old self?