I feel your pain, spending has been a massive issue for me over the last few years. I've spent over £40k in the last 5 years on rubbish. In one week I managed £5k on a car and £2k on a Caribbean holiday.
Having got a diagnosis I decided that enough is enough and I've gone into my bank and given them my diagnosis so I'm now on their systems as a 'vulnerable customer.' In essence they will stop any purchases over £500 and I cannot take out any loans or credit cards with them without a sit down interview.
It's worked so far, but I know that if I get that urge again I'll probably find a way around it. The best tip I've found so far is to wait 24 hours before buying something, as by then the desire has moved on.
Hope you have some success in managing it.