red I have NCed for this thread, for mine and my DCs' privacy as I am ashamed of this in RL. I've read both your threads, I think I was on the playground one.
You can see from my name that I know what your DH is like. I would have read this thread ten years ago and thought along the lines of "all these kind but judgey people, bet they have a glass of two or wine whilst lecturing me about spliffs" and "naice Boden wearing mummies, probably in their 40s and don't know people who smoke, it is normal life no matter what they say" etc etc.
DH and I used to use cannabis recreationally, I had used harder stuff in the past but gave it up when the DC were born. Some of my family and DH's family smoked too, big house and ponies family and the opposite end of the social scale too, so all "walks of life". I worked in a professional job, DC at nursery, never any problems or issues.
We would have a few joints (and glasses of wine) every night. It slowly crept up more so for me than DH to a bottle of wine a night (like a lot of MNers I'm sure) and skunk. I justified this the same way your DH does, you don't need to hear me say it all!
Then one sunny afternoon, a friend of mine and I were skinning up in my back garden as the DC played on their seesaw/sand pit etc. DD came and sat next to us at the table, picked up some rizlas and started miming skinning up, you know, licking the papers, rolling up. She was four. My friend thought it was "so cute" and "funny" but I felt sick. I felt awful. It wasn't the thought of what if she does it at school etc, it was my lovely child thinking this was a funny thing to do. I thought I was a shit mother and a shit role model.
So I stopped (the weed not wine), DH stopped too. It was hard, I'm not going to lie. Cold turkey, ate a SHIT load of food and drank lots of wine. This was in 2004. Haven't had a smoke since. I stopped drinking alcohol in 2012.
I won't say I'm a better parent as I don't think I was even a "good" parent back then. I think I was a selfish irresponsible dick, frankly. And my DC weren't short of money, I would feel even worse if I'm sure if I had been doing what your DH is and smoking money that should be spent on your DC.
My DC are teenagers now and believe me, I am so fucking glad I set them a better role model especially now they've started to navigate the alcohol and drugs stuff. I cant even explain how glad I feel.
My DC know I have used and will answer any questions they have. I think I have a good relationship with them (as good as any teenage parent relationship is!) Their friends sometimes talk to me too.
I've said all this so you know that I know what the fuck I'm talking about. Your DH may well have been a good kind man and father in the past, but he isn't now, and I think you know this. I'm not going to slate him. But right now he is incapable of putting your DD first. The only person who can do this is you. You have to do this. You have to deal with her life as it is today and make it better for her. You understand this and you have the ability to do this (unlike your DH). If you don't use that ability you are failing her and not being the best mother you can be.
I can, hopefully without patronising you, tell you that with 100% certainty, you are going to feel immense guilt in the future (more than the usual parent guilt!). For your own sake, as well as your DDs, take actual active steps to deal with this and get your DD out of this situation. Your DH is an adult, I know you feel a responsibility to him and that you love him, but you have to love your DD more and get her out and hope that your DH as an adult can do the same.
If you can't do this now, I am sorry, I know it's hard, but you would be better ringing social services and let them take the action which is best for your DD.
Maybe try and imagine that you are in a raft which is slowly sinking, with your DP and DD. Someone comes along with a strong raft but your DH refuses to leave, he doesn't think your raft will sink. It's afloat right now, more water is coming in but he says it'll be fine. Would you stay with your DH and make your dd stay? I think as a good mother, you would make sure your DD goes onto the strong raft. Hopefully you would choose to go with her.
Honestly your raft is sinking right now but you have the power to rescue your DD, and yourself. I really hope you can do it, but if you don't think you can please ring SS and explain and let them take action. I'm sorry, five days clean and £50 gifts isn't doing anything, it's meaningless, honestly, your DH is abusing your DD bringing her up like this and you are complicit if you don't take proper meaningful action.
I sincerely hope you and your DD can make use of all the advice on this thread and have a happy secure life.