New here, and so glad there's a community

As the title says, I just joined, and I'm so glad there is a community of people who are in the same situation I'm in. A little introduction, my name is Chuck, and I've been taking care of my wife for about a year and a half, full time. We also have a child of 10 years, so I make sure he's taken care of as well. So, I am the rock in the family. We are staying with my dad, because his house was set up for handicapped access before my mom passed. This is another frustration. She has multiple issues, most of which center around diabetes, and complications of. She can't walk anymore, or stand on her own. So I have to help her with transfers, and clean up after bathroom visits. We are starting to get up there in age, but way too young to be going through this (I'm 44, she's 48). Things have been ok, for the most part. The occasional arguement/frustrating moments when her body decides to throw us the worst it has to offer, and typically late at night. Lately though, her meltdowns have become more frequent, especially when I dare to try to go out alone. I try to escape for a little while, because it's suggested that we (being the caregivers) need to have time to ourselves. I end up getting a guilt trip of "I've been couped up too". I've tried explaining to her, that I need to get away for a few, just as I enjoyed my weekends away when I worked full time. She then takes it personally, so the meltdown ensues. Then comes the catch 22 nightmare I've been living with. I hear her crying in the back room, so I go check on her. She decides that she needs to wallow in self pity, and wants to be left alone, so I become an a-hole for checking up on her. I decide to leave the room, because she's yelling at me to get out, and I become an even bigger a-hole, because I'm leaving (at her loud request) and not talking. If I don't go check on her when she's crying in the room, I become the world's largest inconsiderate a-hole, and get yelled at later because I didn't check on her. So, I end up feeling like an ass, because I've obviously done something wrong. I understand that she is even more frustrated than I am with what her body has done to her, but end up somehow feeling like it's my fault, and I shouldn't want to get out on my own at all, even for an hour or so. It's the post meltdown that gets me the most I think, out of all that. When she calms down, that's it, she feels better. Nothing gets resolved, and I still feel like I did something wrong. This is just scratching the surface, I won't get into it here, because I could take up pages writing about this. I really don't know what to do anymore. I'm tired of being the bad guy, I'm tired of the meltdowns every couple days, and I'm especially tired of constantly feeling like I've done something wrong.