M36 Feeling Exhausted and Undervalued in My Marriage With Wife F36– Need Advice

I’m struggling in my marriage, and I feel like I’ve hit a wall. I’ve been doing everything I can to support my wife, especially after her recent surgery, but no matter what I do, it feels like it’s never enough. I’m starting to feel completely unappreciated, and I wanted to share my situation to see if anyone has been through something similar.

Some Context:

I’ve been with my wife for a long time, and our relationship has been strained for years. Recently, things have been particularly tough. After her surgery, I stepped up in every way I could—taking care of our two kids (both of whom are sick), handling errands, making sure she had everything she needed, and basically keeping things running so she could rest. Despite all that, I’ve been met with coldness and criticism rather than appreciation.

The Latest Situation:

It all started last Friday when I came home exhausted after my second day at a new job. I accidentally forgot to take my medication for severe heartburn and sighed in frustration, which was somehow misconstrued as me being angry at my wife and her mom. Since then, there's been a constant tension in the house, and every little thing I do seems to be blown out of proportion.

I’ve tried to talk to my wife about it, but every time I bring things up, she shuts me down, saying she "can’t do this right now" and accuses me of "looking for problems." When I remind her that it’s her choice to stay stuck in this tension, she tends to calm down temporarily, but it feels like a cycle that never ends.

Toxic Environment and My Mother-in-Law's Influence:

One of the things that I think contributes to this ongoing tension is the role my mother-in-law plays in our household dynamic. Whenever she’s around, the atmosphere becomes much more toxic. She has a tendency to whisper about me behind my back, which I’ve overheard multiple times, and I believe she fuels my wife's frustrations instead of encouraging healthy conversations between us.

I've noticed that when my wife spends more time with her mom or when her mom visits, she becomes more critical and distant with me. It feels like any small issue gets amplified, and I end up feeling like the odd one out in my own home. I don’t believe my mother-in-law is trying to be malicious, but I do think her constant commentary and presence make it harder for my wife and I to address our issues as a team.

Bigger Issues in Our Relationship:

This isn't just about one incident. There’s a pattern of me constantly trying to do the right thing while feeling like I'm always walking on eggshells. Some of the recurring issues include:

A clear favoritism toward our youngest child, while our older daughter feels left out and even called a "tattletale" for expressing her feelings.

My wife’s unwillingness to acknowledge the effort I put in and instead focusing on the negatives.

A history of substance abuse and erratic behavior that has put a huge strain on our family.

What I’ve Done:

I've done everything I can think of to make things better—offering to talk, stepping back when needed, and continuing to support her and the kids. But it’s getting harder to keep my patience when I feel like all my efforts are ignored or twisted against me.

Where I'm At Now:

Honestly, I’m feeling stuck. I don’t want to fight, but I also don’t want to keep feeling like I'm the only one making an effort. I've already started setting things in motion for a divorce, but before going down that road, I want to try one last thing. I'm planning to write a letter to lay everything out constructively and see if there's any chance of meaningful change. If not, I know I’ve done everything I can.

How do you deal with feeling unappreciated and constantly walking on eggshells? Any advice would be appreciated.

TL;DR:

I’ve been doing everything I can to support my wife after her surgery—taking care of our sick kids, running errands, and making sure she can rest—but I feel completely unappreciated. A minor incident where I sighed out of frustration got blown out of proportion, and now there’s constant tension. My wife’s mom seems to fuel the negativity whenever she’s around, whispering about me and contributing to a toxic environment. Despite my efforts to move forward, my wife stays distant and critical, making me feel like I’m always walking on eggshells. I’m stuck wondering how much longer I can keep doing this and would appreciate any advice from those who’ve been through similar situations.