(((Thomas in Ohio)))
I can understand your feeling of desperation. I often fight similar desires. What keeps me going (like it or not) is my 2 daughters. If I didn't have them, I'd happily go.
But, you do have something worth holding onto. Your wife. A person that you love and don't want to hurt.
The guilt does keep me here on Earth in my darker times. In lighter moments, I write down the positives that I can see. Like, nature is beautiful to me. I write about a terrific walk that I took through the country & saw lots of beautiful plants and animals. I avoid watching and reading the news like the plague! The news is waaay too depressing for me to take. I, therefore, also avoid talking about current events. Just try to keep conversations to light subjects. I also see a T regularly and take meds to try to balance my mood better.
I'd recommend trying some (or all) of the techniques listed above, to make it through the hard times. Maybe you should try writing about your emotions, to gain a better understanding of where your emotions are stemming from. And talk about it in T.
Very best wishes to you!