Welcome! You are in the right place. There is a great deal going on there. First, none of this is your fault, but we can enable at the same time being concerned. So yes, take one for the team and stop brining booze home. That does not mean she will not get it herself, it means that you will no longer help her. And if you are concerned about your own levels of drinking, may I suggest you attend a meeting dedicated to recovery? There are many AA, SMART Recovery, private therapist. Even if you aren't an A yourself. Living with her has obviously effected you enough for you to reach out. Start reading every post that you can in this forum and the Alcoholics Forum. You will get an overview of what it's like from people living with addiction. For you there may be al a non or professionals EDUCATED in addiction. Most lay counselors such as pastors aren't. Either way, you must get yourself together. Put on your oxygen mask before you can help her.
The problem is not some mathematical formula for how much one should drink, water in between drinks or not or if they only drink on the weekends or if they drink high end liquor or six packs on sale. The issue is the drinking destroying the persons life, health and relationships. The issue is that the drinking is getting worse and the person can no longer function or control themselves when it comes to alcohol consumption. The first step in A A calls this "unmanageable". That my dear is the understatement of the year! Alcohol will over take a person to the exclusion of EVERYTHING and EVERYONE in their life. Her denial is the addiction protecting itself. That will get stronger. The more the addiction takes hold the more veraciously it will assert itself against any that stands in its way. It will deny, lie and manipulate to survive. I know that sounds dramatic, more like advice for a priest going to an exorcism, but it's close. Her habits, her moods, her personality will begin to shift more and more until one day you think, "who are you?"
Please see a dr. About the depression and meds. Many A's have underlying mental health issues that also need to be addressed. Sleeping 48 hrs is not normal either. My ex could do that, but he also had a pill and H issue. So yes, the meds and booze may be mixing. If she can no longer remember things after drinking and passing out, that is called a blackout. It is very serious, it is abnormal and you are very right to be concerned.
If you are able to have a warm loving conversation with her when she is in her right mind. You may want to express how really concerned you are now. She may or may not be receptive, either way, you must do all that you can to protect your health and well being. Keep coming here! Keep reading and asking questions! Every path has been walked by the members of this group. Nothing you say will be wholly unfamiliar or shock, trust me. Good luck!