Hello, you should consult a physiotherapist for a correct diagnosis. There are many stretches you should do for muscle stiffness. If there is no swelling, use only a hot pack to relax the muscle. Also, avoid bending forward and lifting weight.
And might possible that the exercise you’re doing is increasing your pain, which means it might not be the right one for you.
Next Steps
Consult physiotherapist for correct exercises and stratching also change your routine do not lift heavy weight
Health Tips
Use hot pack