Welcome to your freedom gargoose. Yep, withdrawal sucks - every addict eventually has to come to terms with it, if they mean to get free. The first few days are the worst for sure, but just to give you a heads up: once you get through the first 3 or 4 days, you'll start to feel better and sort of click along. But then at around two weeks, plus or minus a few days, you MIGHT start to feel shitty again for a couple days. Not everyone does, but a lot of us do. I did. I don't know as I've seen any scientific explanation for it, because as AppleJack noted, the poison is out of your body in 72-ish hours. Anyway, just wanted you to know that it could be out there on the horizon so you're not surprised if it happens to you. It's not uncommon.
Post roll, get some digits (shoot me a PM if you want mine), and be quit.
I quit with you today.