I was really resistant to starting methadone too due to the negative stigma of it. I had literally tried every other opiod first.

Methadone has controlled my pain much better than anything else. It's the only drug that helped with the burning pain.

I'm currently on 5mg twice a day and 2.5mg in the middle of the day.

I think the Gabapentin increase is more likely the cause of your brain fog rather than the Methadone. Brain fog is a very common symptom of Gabapentin especially with higher doses.