Trigger warning: drug addiction- my bf is an addict

So awhile back I confessed here that my boyfriend is a herion addict and I can't talk about it, but he said I could online.

He's the most amazing, kind hearted, sweet boyfriend I've had and he's my best friend.

He wants to quit herion but felt like he couldn't work and get off of it and needed money. He has been saving up and has a pretty good job that pays well. He was saying he'd probably quit next summer, a whole year away! Which of course, I worry, but he is at least always honest with me, and is a functional addict. Nobody could tell he's on it.

Well, this week has been rough. He has been struggling a lot with constipation, more and more, lately, as opiates do that apparently. He has had horrible stomach aches and I gave him some magnesium citrate he has been taking... but he almost can't ever poop without crack :/ anyway, I've been really worried for his health long term because of it, and I don't know how to help him. (If anyone knows how to deal with opiate constipation, pls help) he drinks so much water.

Also, not sure if this is related, he had a friend pass away and he has been really upset by that, and how because of the drugs, he felt too bad to talk to his friend. I feel very bad for him in that as well.

Well, today he did not do herion, hoping to get rid of the constipation.

Now he is dope sick, and at the last moment, he has told me he may not sleep & just call off work in the morning because he has "made it this far" without herion!

My boyfriend might quit herion! Which, yes, is great! But I don't know how to be here for him, I don't know what he needs!

I feel so unprepared and im so scared he'll relapse and people die from relapses sometimes!

Help!? He's acting completely unlike himself for the most part so far, and I realize this is going to be so difficult for both of us, and it sucks to see him sick- I'm pretty sure it will get much worse...

And I have no one to talk to about this! I need to be strong for him, but I am scared!

Update: thank you jillian, unfortunately he's not quitting yet :/ I wish your brothers luck, I am glad they are still alive. Addiction sucks so much.