What shall I do? Shall I leave engineering? I have 2 years of drop in my engineering.

Nitin Sir is right if you want to leave the college, it is a fool work. Don't worry about back, just try to overcome from the semester exam by your hard work. All the best!

Its not a wise decision at all to drop from engineering, better to try hard and get through your subjects. Give extra time to subjects in which you are weak. Try to study with focus mind and revise the concepts regularly.