Hi Kate and welcome to your forever quit!
I hope you can put some of the things you have learned from looking into the impulse control issue to use with this quit. You will have a lot of people here to support you as you move forward so please use this forum as much as you need to. Of course we also have an SOS page that has been very effective for many should you ever need it. There is even a thread on that page called Pre-respond To Your Own SOS. There you can write a meaningful message to yourself about why you should never give in again and you can always go there in an instant to read it should you be having a weak moment. It's a great resource.
It sounds like you really want this quit and you are prepared for it as much as any of us can be so jump right in, pledge NOPE every day and lean on us here for support because that's what we are here for