It sure sounds like he's using coke and the brown stuff may be heroin.The scratches all over the counter is from him setting up his lines that explains your razor blade as well. The thing about addicts is that when we are hooked, we are not ourselves. And not only that but our mind is so screwed up that our LIFE revolves around getting high. Every little thing that could pertain to your life has to be around getting your fix.
The lies are also a definite sign of using. You could be the most honest person in the world, get hooked on something and you will lie straight to your mother's face so you she won't know you're using and maybe she'll give you money to get some more. I had never ever lied to my husband (we're together 10years) until I got hooked on Oxy's, from there everything was a lie - how much my paychecks were, why the utilities hadn't been paid in 3 months, how did our car insurance get cancelled, did I go to work today? you name it and we will lie about it.
Him blaming you for all of the bad stuff is very normal for addicts. As Mr. Hyde said, it is our way of denying that our lives are out of control and we have a problem. Our "habit" isn't why we lost the house and I can't pay the utilities. It's because your a b$%^ch and spent all the money and turned them off.
I'm sure if he wasn't using he probably wouldn't be this harsh with the lies and everything (hopefully not). You should decide if this is something that you want to get involved in, getting him help, or not. Good Luck and let us know how you make out!