You're injured. You may someday be healed, but for right now, you're injured. That's not a moral statement. You're not a bad person for being injured.
You can't meet your expectations right now. Injury is like that. Forgive yourself for it. ("Forgive" is the wrong word, because it implies moral fault. But to the degree that you blame yourself, forgive yourself.) Then try to work on healing. That's what you need right now. (Athletes don't try to play on pulled hamstrings, but they do work on rehab.)
I can't tell you what "rehab" looks like for you. All I can say is that you need to stop beating yourself up for being broken by trauma. It's not a failing.
For what it's worth, I'm praying for you.
I lost my son to suicide earlier this year, and I hope you don't do that. It's absolutely awful for everyone who is left behind, and they are never the same afterwards.
Keep trying therapists. Some specialise in particular areas, and perhaps there's one who specialises in your particular burden. Someone said to me "therapists are like shoes. Keep trying until you find one that fits."
Consider residential care -- check out of the daily pressures of life for a while and be with people who can help you all the time rather than once a week. I hope your family would be supportive if you made it clear that you were considering suicide.
Our son hid his pain from us, and while we knew he was struggling we didn't know the magnitude of it. If we'd known he was considering suicide, perhaps we could have helped him through it.
Much love to you. If you ever need to chat, I'm @gnat on Twitter or [email protected] in email. As we say in New Zealand, "kia kaha!" (be strong).
Some decisions are not right or wrong, some decisions have no serious lasting impact. What do you want for dinner? What do you want to watch on tv tonight? There's no choosing wrong, there's no perfect answer.
Concern that you're a poor husband sounds a lot like imposter syndrome. The thing is, having those concerns means you're far from being a poor husband. Bad husbands don't care if they are bad husbands, and usually convince themselves that they aren't the problem. Communication is the biggest most important thing in making a relationship work. Focus on that. The Seven Principles for Making Marriage Work is a book by John Gottman that will help.
Every adult on the planet is an ineffective adult. It sounds like you have a lot of high expectations of yourself. No one is perfect. No one has all of their shit together. No one person can do everything on their own that they "should" be doing to be a "proper" adult.
You have to remember to show yourself some compassion. What advice would you give to someone that came to you with these concerns?
I recommend reading "The way of the peaceful warrior" by Dan Millman.
I too am naive and overly trusting. I would rather live my life with the occasional screw over and manipulation then living jaded and distrusting. I want to live a life of kindness and love. Sometimes it doesn't work out, but more often it does.
This too shall pass. Suicide only ensures that things can never get better.
The simplest "food for the soul" is to eat, shit, and sleep. Everything else can be addressed later.