Hey Red, really sorry to hear your story and sorry for the loss of your mum. Asking for help is a big step so we’ll done. I don’t really know if it is your ex that is buying the drugs but that is ridiculous and you need to cut that person out of your life even if only temporarily.
Have you tried Cocaine Anonymous or Narcotics Anonymous? They have meetings all round the country and lots of people say they are really helpful.
Good luck and no need to apologise for posting! X