Your psych meds should always make you feel more like yourself, not like someone else.
I am on Escitalopram 40mgs (max dosage) and it has helped for a couple of years, though now I'm starting to have what you call "burn through" though not as bad, when my moods started to become a problem again my doc hesitantly put me on 50mg seroquel to help stabilise me. It's helped but not fully-but it's just been ten days on that.
Before my "burn through" and moods starting to go haywire-It helped me quite a bit. I wasn't getting angry at stupid things (like throwing a pen across the room after five minutes of trying to get it to write), I wasn't assuming things that went missing were stolen or moved just to mess with me, and I wasn't crying at night anymore. All of those symptoms dried up enough that I attempted to low down and lower my dosage.
Not a good idea. When I went lower it was like a smoker going cold turkey-not surprising since irritation and irrational anger are part of my PTSD package. So I keep on it.
If your meds are not working you need to see your doctor or get a psychiatrist to look into other options (where I am my GP is permitted to prescribe psych meds), perhaps add in something that will help.
Psych meds are a very much try and find what works area. Sometimes it does, sometimes it doesn't. You need to be open about your concerns so that the right solution can be found for you. If you start getting concerned, you do neeed to bring it up so they can be adjusted, as a number of things can affect our brain chemistry in a variety of ways, even just an environment change can alter it.
Do talk to your doctor and bring up your concerns.
I hope that a solution that doesn't have you and your spouse concerned can be found soon.