mm I am so glad that things have moved forwards a teeeeeeny bit for you. That is progress, it really is. Well done.
Please don't respond to all the pms. Just focus on getting better. If you think responding to some pms will help you do that, then yes, respond to them. As for mine, if we don't live near each other then I can't help so there's no need to respond.
As Crapola said, your DS won't remember this. Or if he does, when he's an adult you'll be able to discuss it with him and he will understand you better and respect you for your honesty, courage and determination to give your children a good life.
As far as your mum's offer is concerned...I tend to think that when you're stuck in a hole, if there's a way out which is not damaging, it's always good to give it a try if only temporarily. Trying something new can have a marvellous effect on the spirit and it could enable you to go back home with renewed motivation to change something in your life.
However, you do raise significant concerns about going to your mum's, and I don't really have any answers, not knowing the house layout/ personality of the smoker. If there is any way you could all work around those things, I think even a month at your mum's place could be a good start.
Rooting for you.