Someone give me strength....

Forgive me if I ramble on a moment....but have to write it down before I go bonkers....as the cat in the pic is how I feel at present, gritted teeth and ready to pull hair out, it's going grey anyways!! AND SCREAM !!!!! My youngest son, my problem child, has become a big problem again....and it's really got to me badly today. Won't go into too many details coz if I start I won't stop...but 18 months ago he went into rehab for a cannabis problem which with his ADHD was very addictive. He came out clean but this week he had a big conflict at his work and got the sack/ walked out and now he has started using again. I don't know if I have the strength to cope again, without me going off the rails. He was here a little while ago, and was stressed out to the max, and had been using, but he did eventually calm down again and we were able to talk to him. Don't know how much he took in but I am hoping something sunk in....I really don't know if I will cope if he heads down that road again. Hubby won't have him here if he uses and has told son that as he won't put me throu all what we went throu again. Son has a partner 7 months pregnant and a 3 year old girl who he loves so I am hoping and praying he can see the damage before he go's that road again. Pleazzzzzzzzzzzzzzze let him be okay again, find another job and house and move on with a stable life.