oh OP.
I dont judge you, but I think youre at serious risk of having your child removed from you, and no matter how much you love your man, there is no man in the world worth that.
Ive been a drug addict who stopped the moment i found out I was pregnant, but ive been in that world, and I have known many who didnt, and had their children removed. They all really really loved their children.
You said you can already sense your dp is getting bored, and you have already had SS involvement.
This thread isnt about the rights and wrongs of your inlaws or whether smoking weed is as bad as doing other things. Your man has actually said that hes not giving up weed on top of the other things he has had to give up - hes not giving up for the right reasons. Hes giving up because you want him to. That has such a low chance of working out, that you mustnt trust it.
Sometimes loving someone means stopping enabling their self sabotage. You can love him. Im sure he is interesting, enigmatic and clever and all those attractive things. He is also trouble and if he hasnt been able to put you and your child first in the last nearly 4 years since you got that line on a pregnancy test, then why the faith now?
He isnt ready to give up. Hes put you in the parent role thats making him do it reluctantly. You dont need to take on that role to anyone except your own child, who im sorry to say you are putting too far down on your lst of priorities. Youre prioritising your love affair with a broken man, and you could lose your child and if SS are already involved, then you actually probably will if you dont get your shit together and smell the coffee. Im sorry thats harsh but ive seen it happen. It happens all the time