"This man never used to be like this. I feel so cheated that I am stuck with other person most of the time."
I used to feel cheated, too. But not by my boyfriend's alcoholism, his behavior, or his constant lies. I felt cheated because I was allowing another person to treat me this way. Then I realized that I didn't have to accept unacceptable behavior any more. I could choose a different life for myself. I could choose a healthy partner. I could choose a life that's free from the effects of another's addiction. I could choose to let go of the things in my life that were causing me pain.
The bottom line is we all have choices and you don't have to live this way. Today you may choose to tolerate this type of life. But tomorrow you can choose otherwise. You can be miserable in the company of an alcoholic or you can be happy on your own. The choice is yours.