Knots can be because of prolonged wrong posture or after an unacoustomed movement or exercise or strain on ur back...
Muscle relaxants do help but knowing the correct cause is required to come to the proper treatment of ur agony.
Clinical examination along with required investigations will be of help.
Next Steps
show an orthopedic doctor at earliest
Health Tips
avoid prolonged walk, stand or sitting in awkward positions try to take full back support as u sit...
avoid phones and laptops and reading in bed....
hope u recover soon