Okay.....we must be related or at least in the same family??????
WOW! As I read your post I began to see myself in all of that family chaos! Its amazing how in-laws can interfere BIG TIME! However, let me tell you how to handle them. Don't confide in them. Do Not Tell Them Anything!!!! For some reason my in-laws do the opposite of what they say they are gonna do. Most of my problems ended when I stopped confiding in them and I started posting more here. Alanon is a great place to start because not your sister in law or your mother in law or you can fix him. He has to do that himself. You have to focus on yourself and your well-being. Learning how to cope with the Alcoholic is a long process but the more you read and post here you will learn quickly. I hate that you are going through this, I've been there right where you stand. I made it through it and so can you. Others will be around soon to give you more advice.
Please keep posting because it really helps. We are here for you!
Hugs from NC,
2many2count