Its a sciatica...piriformjs is a one of the rare cause for sciatica...
Next Steps
sit straight while online classes...u can use belt for back support-LS corset...
hot water bag fomentation, T.DAN-MR tablet two times for 2-3 days
Health Tips
still if it doesnt get relieved then consult orthopaedician either by video call or on person.
and please dont google ur symptoms otherwose u will get crazy diagnosis