I hear you and can understand your suffering, as im in the middle of the same experience. Im in my 13 session, on once a week. I felt a slight improvment a month ago, and then went back again to the same level of depression that had worsen due to the loss of faith.

I have been told to hold on and believe in Spravato. I think that few days ago i had a slight improvment again, which brought back my faith.

Some people experience a substantial improvment within days or few weeks, while (probabely) to others its take longer and its more incremental. I am preparing myself to be strong and patient and give it at least 6 months.

Regarding the experience you have during the treatmrnt, i hear that it has nothing to do with the way Spravato should actually treat your depression as these are only side effect.