Child of an addict, feeling lost (long post)

Just need to vent a little, if you have any advice or similar situations I would really appreciate anything you have to offer.

My father was an meth addict when I was growing up. I lived in a house with no electricity or hot water and was always around drugs and addicts. I spent most of my teen years trying to save him from drugs. I finally had enough and cut him out of my life 1st 18. He got clean and has been clean for about 7 years! It took along time but we have rebuilt a relationship and are very close. He's a great papa to my two children.

My dad hasn't had a stable job, he really doesn't try to do anything because he lives with my grandparents for free and has most of his life. I have helped him financially for many years to try to keep him from going back to drugs. I am more of a parent to him in our relationship.

A couple of months ago he wanted to get a Facebook account, so I got him a new smart phone and set up an account for him. Slowly he started calling less and visiting less. I hadn't heard from him in a few weeks and I was worried about him.

I invaded his privacy and checked his Facebook messages. I found out that he has been doing heroin and hanging around a prostitute junkie. I talked to my grandparents and they really were not going to do anything because they didn't have evidence. So, I waited and continued to check up on his messages.

Today I saw he got some money and was going to buy 50$ in herion. I freaked out, I confronted him. He denied it first, then admitted to smoking it a few times. He didn't say he would stop hanging out with the junkies. So I told him I couldn't have a relationship with him until he got back on track. His addiction almost ruined my life for many years.I can't go through that again.

He is furious with me for looking at his messages. I am So worried and scared for him. My heart has been broken again because of drugs and addiction.

I don't know what to do now. Will he ever forgive me for invading his privacy? Did I do the "right" thing? Any advice, please?💔