Hi-What is your gut feeling telling you? Is it better for your son to live in a single parent household that’s happy, or in an unhappy situation? Think carefully, because as much as you want to keep your family unit together, overcoming an addiction can be a life-long battle.
There are some things that stand out for me in your post re: your partner;
1. He is still using, but is denying this and is meant to be in recovery. Not detox, but recovery-which is meant to be the next step on from detox. How can he detox though when he’s still using? He’s not ‘clean’ therefore still.
2. He’s been using for years. This makes it hard to kick an addiction/easy to relapse.
3. He blamed you for an offence that he committed. HE GOT YOU ARRESTED for it. Is that love? (Answer: Hell NO!)
4. You say he’s ruining your life. YOUR life. It’s not his to ruin though is it? His poor choices as a grown adult should not detrimentally impact on the quality of your life. That’s not fair on you.
5. It’s not uncommon for families where a parent has a drug addiction, for the quality of life to shrink. How will he be at parent-teacher meetings? Do you feel your son is safe with him if left in his care while you’re out? Who’s he bringing into your home and what are they like?
If you separate, he can still be in your son’s life. You’re not cutting him out completely. Maybe, if he has a parenting order of, say, Sundays-he could try to aim to refrain from using on Sundays for when he has your son over. Your son still gets to see him and who knows, it might give your (then) ex, a target to aim for in not using 1 day per week, which might help his recovery journey.
Depending on what drugs he’s using and where, I’d also be thinking of my own and my son’s health. What are you breathing in second-hand? Is there powder/residue around the house you might come into contact with?
What if your son starts using at some point, because seeing his dad using regularly has become ‘the norm’ for him?