Hi Tracey,
Welcome to the Forum, a great place to share your story and hopefully get help and advice from other people in a similar situation.
I have found the Adfam site to be a god send, have you read the Theresa thread? There are about 6 Mums on there all with Sons who are addicts, it’s so good to be able to chat with people in the same situation.
My Son is an addict, alcohol and cocaine (such an evil drug), he is doing ok at the moment, but have lived through it with him for about 10 years, like living in hell.
We have to learn to look after ourselves first, which I find very difficult to do, as you say the constant worry is terrible.
Keep chatting on here and read the other threads, I really think it helps.
Take care.
Dx