stretchlying and inner corset

Hi Esther,   I've been working on stretchlying and stretchsitting for a little over a month now, but I've started having some difficulties. Sometimes I feel discomfort in my neck and upper thoratic spine when stretchlying even though I have tried two different pillows and adjusting the pillow higher or lower under my shoulders. I also have sore back muscles all the way from my shoulder blades to my lower back and itchy skin all around my spine; could I be over stretching too much too soon. Other symptoms include sensation of  pins and needles in different parts of my body but not at the same time. I got diagnosed with a protruding L5 disk and scoliosis about a month ago but the disk injury happened recently in february; is it safe to practice using my inner corset with my recent disk injury? Thank you for your time.