That feeling is one we all understand. Every single person here has felt that deep shame and regret.
The good news is shame means you know you have to change. It is possible to change, if you ask for help and take it one day at a time. And there are so many benefits to it! Sassy has a great list of all the things she gets from her sobriety - you may recognize a lot of these yourself (scroll down to the bullet points for the list)
(scroll down to the bullet points for the list)