Welcome, Andrew!
You're in the suck, embrace it and remember how the next few weeks feel so that way you will never want to go through this crap again. Dont dip your toe in the water jump in and make your word early every day.
Drink water until every time you think about it you have to piss, it will help get rid of the nic. When you crave do pushups or burpees if you cant take a breath you cant crave.
Take it minute by minute, then hour by hour then day by day. Whatever you need you can find it here. I quit with you