You can do it my man. I started smoking when I was 12 and quit when I was 18. I think once it wasn't illegal it didn't seem as cool anymore, and I never did truly enjoy it so it wasn't so hard for me to just quit cold turkey. The alcohol has been harder for me. I still drink some beer or some vodka almost everyday. I don't get drunk to where it affects my job or my relationships or anything like that, but I know its not healthy. But honestly just typing this, just mentioning it, makes me crave a drink. Addiction is tough, humans are creatures of habit, but if you really want to make a change you can do it.