When you are very active it is more common to injur yourself for numerous reasons such as over exertion, not enough rest or recovery time etc Exercise stresses the body so it's important with enough rest time inbetween workouts.
I dont know why/how you injured your back but it is super important that you rest now that you have a back injury because if you dont, or you begin exercising too early then you can cause more pain and injury and have to spend even more time resting. So its better to just rest a few weeks, and the time that your body needs to heal properly. Instead do some light stretching so that you don't get stiff. But i would follow your doctors instructions if you have gone there - which could be helpful.
Pain is your bodies way of saying that something is wrong and that it needs rest and recovery, that now you need to rest that muscle and whenever you feel pain because you move or touch a certain area... that is your body telling you to not do that. So listen to your body.
I know this can feel tough and terrible at the moment, but find other things to do with your day. Distract yourself, enjoy the rest because soon you will be back to your normal self and have lots of energy. This wont ruin progress or make you fat or gain weight. This is rest time so your body can recover from it's energy and you can go back to feeling better again.
Dont let that voice in your head control you, instead fight back and know that you are being strong and doing the right thing at the moment!