I'm probably projecting here, but if you go back and replace "validation" with "support" does that still resonate?

I'm going to REALLY project here: My wife and I have been coping with depression/anxiety/trauma issues for over a decade, and I'm personally struggling with a lot of things because of it. One part is the ongoing inequality of supporting someone who isn't capable of equally emotionally and mentally supporting you back, while also supporting your family, AND supporting yourself. Its exhausting, you can't ever put that weight down, you hold everything up for everyone and you try to be the best person you can be. Every mistake you make, every time you're not patient or understanding, when you have your own emotions on bad days and say the wrong thing or something the wrong way, or don't say anything when you need to, and things fall apart around you and its so bad you become fearful of ever needing anything from anyone and turn inward. They do what they can, you can't fault them for their situation, its worse than your own and at first its what drives you to shoulder it and carry everything but eventually the resentment and anger builds, and as time goes on what support system you have bleeds away. You feel like you're crumbling, and you want someone you can lean on a bit, someone to say its ok, you've been doing great you can relax and take a breath, i've got you, i can support you, focus on your feelings, your struggles. I can help carry your weight for a little bit you've done it for so long for me.

And after all this time supporting her, she's getting better and you're left in some ways worse off, and to add to the inequality of it she's not offering you the support she's had for years.

I don't have answers but it sounded like you're looking for someone who understands your feelings and frustrations. I don't know if I do, but maybe we understand each other a bit in this.