J

Ouch

Today i was at school sitting in my chair and i kind of leaned back and out of sudden my lower back started hurting this usually happens to me but then i stretch it out and it gets better but this time it hurts a lot like when i bent down and then slowly get up it starts to hurt so i thought i should stretch for a little bit for lower back it worked for a little bit but then it started hurting again and i feel like i pulled a muscle but that doesn't sound reasonable to me so i went to the school nurse and she said i should put ice on it and i did but instead it made the pain numb but then again it started hurting again then she said i should take a rest for about a week but i feel like i am going to gain weight if i take a rest for 1 week so what are some low impact exercises that help with lower back and how long should i rest?

Edited