Tess, I accessed a local service called 'Addaction', which as far as I know was the NHS provision for my local area. I was recently told it doesn't exist any more- I don't know whether that's the case or not.
Anyway, they offered me a number of sessions with a substance misuse key worker. I also attended a weekly women's group which was run by the same organisation. It's hard to pinpoint exactly what it was that helped- I got on very well with my key worker, which was a good start. I really liked and respected her. Secondly, the women's group was an eye-opener. In my case, it brought home to me how small my problem was compared to the problems most of the others had. I had always lived a privileged and comfortable life. I'd finished my education, was financially secure and had a supportive family.
Many of the other women in the group had very sad histories and were living shambolic lives. Many had grown up in care, had abusive/neglectful/addict parents, suffered childhood sexual abuse, abusive adult relationships.... It was easy to see how so many of them had ended up where they were. Several of them had had their children removed from them, because of the extent of their addictions.
It was extremely sad and humbling and triggered something in me. I suppose it was the realisation that if these women could try so hard to recover, then I certainly could too. And it became obvious that I had perhaps a better chance than many of them, as I had a number of advantages in the shape of family support and so on.
Sorry, that turned into a bit of a long-winded explanation, but that is the combination of factors that caused some sort of change in me.
It may be that you yourself have had a very difficult life, and if so, then I'm very sorry, and hope my post doesn't sound insensitive. But I do believe anyone can overcome addiction, even those who have the odds stacked against them.
At the place I attended, they had 'Recovery Champions'- former service users who had experienced success in their recovery and who were acting as mentors for current service users. One of these was a man who had had an horrendous childhood, who began using drugs at a young age and had spent the next 30 years in and out of prison. He had been clean for some time when I met him.
As an aside, he turned out to be a bit of a sexual predator, in my opinion. But nonetheless, he'd got rid of his drug habit, which was the point of my telling the anecdote :D
All the very best of luck to you OP.