Nearly every singer I have coached has at one time or another experienced some degree of vocal strain. You can use the exercise I describe in this short video to reduce strain and increase your resonance at the same time.
Resonance is the way to get volume and quality tone so your voice sounds “big.” If you strain, it creates tension and this reduces resonance.
Try this exercise and let me know how it goes.
I wish you continued success with your singing.
All the best,