Hi Frank
Backs / spines are weird things, they are the carriers of nerves which sends messages from our bodies to our brain .. our central nervous system...
Is your pain in your lower back? You could have caused inflammation in the muscles surrounding the are, causing this pain, if not treated, the pain will remain. Are you taking anti-inflammatory pills to reduce this swelling ? Have you been and seen a doctor for it?
You mention that you did weight lifting before summer break, I'm not judging you in any way, but could you have over-did these weights, lift more than you should, straining whilst you lifted.
As you haven't lifted during the break has helped, however, you gotta keep up light exercise, to stop your back seizing up. It is hard to keep active when you are in so much pain, but keep the movement going.
Even if it is 'floor exercises'.
You need to strenghten the surrounding muscles also, to protect your back, before you take up weight lifting sports.
Please see a doctor, and get some medical help with this ...
You take care Frank, and please keep in touch with us.
Ginger