Chronic pain after Covid-19

I would be grateful if you could help me with a case.. A 45-year-old female patient, previously very active, has been attending with persistent, debilitating pain in her muscles and joints, lasting for over a year following Covid-19 infection. Extensive imaging and blood work, have ruled out autoimmune conditions and neurological disorders. The patient has tried a range of treatments ranging from simple pain relief, physical therapy, and low-dose SSRIs, with minimal relief. The pain significantly impacts her daily functioning - she has gained 15kgs since due to inactivity. What would you recommend as the next step in her treatment plan?