Hi

Not sure of your age bracket, but when I took up the guitar at 55 I had numerous aches and pains and there are times I still do, but that is more an aspect of arthritis.

For the most part the back pain stopped after a few months. Playing guitar stretches and stresses parts of us not used to being stretched and stressed.

You may want to ride it out for a bit and see if it subsides.

Good luck with your studies