Struggling

I've been on Fluoxetine/Prozac for about 2 months now. I started on 10mg and just got bumped up to 20mg 7 days ago. I am struggling. Even typing this out is a whole ass ordeal. I have several side effects but the most concerning is the MAJOR brain fog. Like zombified zonked out cannot concentrate or do my job effectively brain fog. Now, 2 days ago, I accidentally took just 1 pill instead of my 2 (10mg each out of habit) and I was GREAT the next day. I talked to my doc about alternating doses (10mg, 20mg, 10mg.. etc) until my side effects even out. Has anyone else done this and did it work? Or should I just see about dropping back down to 10mg? Any suggestions would be appreciated. Thanks!