Forget the worry about "what if I am wrong and I walk away", because the chance of you being wrong is very, very small.......think instead of "what if I trust my gut, what if I am right, and I DON'T walk away".
You will stay with a lying, manipulating drunk and life will be miserable for you.
I also believe if it looks like a duck, waddles like a duck, and quacks like a duck ........then it IS a duck.
If he looks like he has been drinking, and SMELLS of drink, HE HAS BEEN DRINKING.
Now it is up to you to decide what your response is to be, to his lies and breaking of your boundaries.