As per your complaints (right thumb numb) this is related to Right Median Nerve
compression.The root value of this nerve is C5,6,7,8,T1. The main area of distribution of the median nerve is forearm (C 5,6,7) where it supplies most of forearm flexors, and hand (C8, T1) where it supplies muscles of thenar eminence (thumb muscles). During the pull your neck was tilted to right and your numbness
is also on right side thumb. It concludes that there is compression/pull over C8 and T1 roots. Hence you need to workout at this level. This is advisable for you to consult a Physiotherapist who is certified on "Mc Kenzie Manual therapy techniques for spine" for a clinical examination and treatment.
wish you a quick recovery soon.