Addiction?

Hey girls, I wanted to post this somewhere I could stay anonymous & receive good advice.

I think my fiancé has relapsed with his pill addiction.

Before you read that and judge, let me explain some more.

My fiancé is 23, he became addicted to pills in high school and quit them a couple years back. He was smoking weed in order to help his addiction, but he recently quit that as well because we are wanting to move forward in life. His mom is a bad drug addict as well, but he has nothing to do with her. Recently I started to notice he is losing weight ( he’s already really small but started gaining some weight, but now he’s losing it again) it could be from his high metabolism though. He also can’t get hard, he’s been having trouble getting hard even when he really wants to and gets depressed over it. He’s also been very depressed here lately, all he wants is to cuddle me. The reason why I’m thinking, is because he’s been going over to this known pill heads house & working on his vehicles but I never see the money for it. (He’s a certified mechanic) He never wants me to go, but i know he actually is working on them because he’s shown me messages where the pill dude won’t stop blowing up his phone about fixing his brakes. I decided to get snoopy ( I know, I shouldn’t) and seen where my fiancé asked him if he had any “perkys” ? Now I’m worried. He has been having back pain and such , so bad to the point he has to put icy hot on it, but I’m still worried he relapsed. I care about him a lot & just hope I’m overthinking it. I come from a low income family where my aunts are on drugs & my dad takes care of their kids so I know how addiction works & I know you can’t just ask them because chances are, they won’t tell you the truth. I just need some advice. How can I help him? Even if we were to break up, I care about him and his whole family and want to help him either way.

*his family has never knew about his addiction, he hid it very well. The only one who knew is his sister.