My mom ruined my trust with my toddler...

Justice • son born 12-9-16👦 missed miscarriage 7-12-17 at 10 weeks👼 blighted ovum 2-5-18👼baby girl born 11-25-18👧

So my mom is an alcoholic. Her and my dad split up 3 years ago. After that they both went down hill . My dad is an alcoholic and is skinny and frail. He shakes horribly whenever he is starting to dry out. My mom on the other hand. She’s way worse. We drove 1,000 miles to see her before we have our second baby here in a month and a half. We brought our almost 2 year old son with us. She has gone to rehab twice and almost died once. She has a a breathalyzer in her car now and is on probation. When we first got here things were great. She was sober and we were having a great time. I have two siblings that are much younger than me (11, and 16) that still live with her and

My dad. So anyway I thought she was sober until yesterday she took our son to the store with her and my younger brother to do some shopping while we went to take care of my dad. And it went really well. My son loved it and had so much fun. She was in a great mood and was so excited that I trusted her to take him somewhere without being supervised. So last night I had a cousin come to town to go to dinner with my husband and I. My siblings were at home with my mom and she was cooking a big dinner and had plans for a movie and popcorn after. I was happy to see how excited she was. Well I get a txt from my sister saying “come home” about an hour into our meal. We hurried home to find my mom was drunk. And apparently had been since shortly after we left. We were also informed that she yelled at him and scared him to the point she terrified him. He grabbed onto me for dear life as soon as we walked in the door and started saying “ sorry” over and over again. I was instantly angry. I thought she had changed she stayed sober the whole week we’ve been here until we were gone for an hour last night. I cried and told her she will never be left with my children alone ever again. We ended up fighting and I took my siblings and my son and husband and we went to Walmart to cool off and let her go to bed. We got back an hour later and found her asleep on the kitchen floor. We woke her up to go to bed and she started talking a bunch of nonsense that we couldn’t really follow. Stuff like “ how did you get here? Your dad brought you?” And more weird stuff. So we got her to bed and we went and packed all of our things to head out first thing in the morning. Well we just woke up and my husband and I and ready to go and I just don’t know how to talk to her today about us leaving early. But I’m so heartbroken and angry that she would do this that I just want to scream at her and run out. Some words of encouragement that I’m not a horrible mother for trusting her to watch my son for an hour last night would be appreciated. I cried for hours and held my baby. I felt so awful. I thought she had been sober for almost 6 months now. I’ve been sick to my stomach all night and I’m 31 weeks pregnant and I know this stress is bad on me. I’m just ready to go back home and pretend that none of this happened and wish my son had a grandma and grandpa that were normal human beings....