I really hope for your sake its nothing serious i been injured for 6 years now after doing squats and deadlifts.

I would get this checked right away dont take any chances and get some x rays.

After 6 years of shit i found a chiro (Competant this time around) that made me take some x rays, he found a calcium depot in one of my neck vertebrae and made me work on my posture.

If you wait to long and are in pain most of the time you tend to bend your head forward to minimize the pain at least thats what i did and my posture is hell today.

Good luck bro and hope everything will turn up fine.

If your back is swollen lower back its alright to ice, but dont do it more then 10 minutes at a time