I hope that you can both decide on what meds to take and which ones not to, and how to regulate it all like when he was doing ok... going back to that immediately is what I would try.
Please don't think you haven't progressed. You have. I know the feeling though, and am trying to pass along to you what my T shares with me (no charge

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Setbacks happen. You have progressed, you have had better days since 4 years ago, and you have learned SO much in that time. Yes, this was a setback, but now you know, and now you are ready to make some firm agreements about the future (and medications.)
We have disorders, but we cannot use them as an excuse for not taking care of ourselves. Yes, much might be cause by the meds and the disorders, but then we have to pull ourselves up by the boot straps and take responsibility and try to figure things out again.