I have also been through long-term depression and misdiagnosis (frontal temporal dementia, psycho phenocopy) that had me taking 21 meds a day for 8 years. I found myself unable to get my medications refilled and ended up off my meds cold turkey for 6 months, leading me to go crazy. Once I made it back home, I could not get in to see my or any other neurologist for another three months. My primary care doctor recommended that I Baker Act myself so they could help level me out. I did. They restarted a couple of my meds and sent me home. I was able to get in to see a Psychiatrist. He thought Ketamine treatments may help with my depression and any lingering side effects from being off the meds.
Ketamine injections are a supervised treatment (in office) and were not covered by medicare insurance. We agreed to try 8 treatments (every other day or two and three times a week). We started at 30 mg and increased to 40 mg. I weigh 200 pounds. This small increase around treatment 5 was so strong that I could not imagine some patients using 300 mg treatments. By treatment 12, I felt my depression was gone, and I started being concerned about getting addicted. Doc thought my remaining issues may be physical. He spoke with my PCP, and they agreed to work together to see what was causing pressure on my head and eyes, migraines, dizziness, and what I described as my mind being scrambled (not foggy or cloudy).
I was still months away from a neurologist appointment. So, My. PCP said he could order an MRI of my brain... Results came back showing I had a Vestibular Schwannoma (a non-cancerous tumor at my left ear nerve). We agreed to suspend treatments for now. (I have had no withdrawal issues from just stopping treatments.). Now we are on a whole different adventure. But not depressed!

I guess where I am going with this discussion is about your concerns with Ketamine treatments.
They say ketamine disconnects your receptors in your brain, and as the ketamine wears off, everything re-aliens or connects back where they are supposed to connect. It is a trip. The Ketamine takes effect fast. You are not supposed to fight it. Just let your mind go wherever it takes you. I would always pay attention to the corner of the room. It would show multiple visions (like double vision, but 4, 5, or 6) and thoughts of so many different realities at the same time, seemingly dependent on how a word used to describe the moment was used (or defined) in your thoughts. It is a super spaced-out experience. It somehow puts life in perspective. Opens you up to possibilities and other solutions available in everything. You don't have to be stuck. It worked for me.

It is not for everyone. It was described to me when I asked if it was addictive. The answer was "no more than Alchahal." I like Bourbon now and then, and I enjoy a glass of red wine a few times a month. I have never had the addiction. Anyway, I stayed keen on any sign I may be "needing " Ketamine.

On the negative side, Ketamine does raise your blood pressure very high for 4 to 6 hours while it is in your system. It will make you need to urinate... so pee before you get dosed. Ketamine felt very hard on my body. The day after, I felt like all my organs had been beaten up... sore.

For me, it was worth the discomfort.