Have name changed as I’ll likely talk to people IRL about this. Happy for MNHQ to confirm I’m a regular.
Cleaning out DS16 bedroom today and have found a bong. No idea how long it might have been there. I had actually suspected something was going on with him recently as his mood has been low and he seems to have decided GCSEs don’t matter. 
for the past few months he has been going off for walks in the evenings, sometimes to meet his friend and sometimes alone. I initially thought he had a girlfriend but he is adamant he doesn’t and I believe him about that. I thought maybe going to smoke weed but he doesn’t smell of anything when he comes back. Last week I asked him if he’d been crying as his eyes looked a bit red. I suspected he’d been smoking weed but didn’t ask him that as I’d no proof and he would have just hidden any evidence. To clarify, today’s cleaning session wasn’t meant to be a snooping session, his room is a shit tip and I need some cups and glasses back in my kitchen. He got a job during the summer so has lots of money to but as much weed or whatever he likes. This seems to have coincided with the recent change in mood and the “GCSEs don’t matter” attitude. We had a row this week as he is refusing to go to revision sessions his school are doing for his upcoming (November) GCSE assessments. He says he just doesn’t care. Doesn’t care about anything. When I pushed him on what that meant he wouldn’t clarify and just tried to confuse the conversation. I said he sounds depressed and I can make an appointment for the GP. He said he isn’t and doesn’t want that. I think he is and he should but obviously at 16 can’t force him.
So advice. How do I deal with this? It’s just me. There is no dad. And there is a younger, very impressionable DC with SEN and stuff going on too. I’m about at my limit with what I can cope with but really do not want to explode and fuck up my handling of this. His dad started smoking weed when I was pregnant and quickly became a complete arsehole and moved on to other stuff. I left him before DS was born. I haven’t told DS about his dad and the drugs.
And I mean really how would/did you deal with this, not the MN overreaction of making him move out or taking all his belongings until he falls into line again. I mean real advice.
TIA