Sons wedding in 12 weeks and I haven't managed to stop

I am 60 and hve been picking on and off since my early teens. Although I had a long gap when I didn't do it. Currently it is bad. I have had CBT which didn't work, I am just coming to the end of some hynotherapy and that doesn't appear to have worked. You would think with an important event coming up I would be motivated to stop, but I can't and the more I try the harder it is. I am worried sick about what to wear.... must have sleeves, but be below my knee. I love fashion and clothes and this will ruin what I can wear for the wedding. It is so depressing. I would like to say it is good to see so many people with the same thing, but it isn't. YOu are all going through this real trauma and it is dreadful. I cover it up well, have a professional job and loving family, but getting so tired of it all now. I have come back on here after a gap of quite a while in desperation to see if there is anything I haven't tried. Thanks for listening.