I'm so sorry to hear you are suffering with pain and fatigue. I agree, sometimes I don't know what is worse, and I know they contribute to each other and especially with our ability to cope. How long has it been since your Rituximab infusion? I find mine peaks about 3 months after the infusion. It may be time to check back with your Rheum? I have heard that sometimes they decrease the time interval between Rituximab doses.
Rixtuximab is rarely one of the first choices for biologics. Have you tried others? How is your sleep? It is definitely a factor in a complex equation. My Rheum referred me to Sleep Medicine and they were able to help me improve my RA symptoms of pain and fatigue some. Definitely no cure, but every little bit helps.
I Hope your flares are resolved soon, Jo