I had the same surgery five years ago only at C6-7. The recovery is really rough. The first 2 or 3 weeks after surgery were horrible, I had to take a lot of medication and I lived in a recliner, it hurt to move. It took me 3 or 4 weeks before I could ride in a car because the motion and the bumps made me hurt so bad. So at 6 days, I don't envy you.
A lot of what you mentioned I experienced as well, your shoulder pain is kind of concerning, have you talked to your surgeon about it? When's your 1st post-op appointment? If your meds aren't working, get them to script you something stronger. You got a lot going on right now, they need to make you as comfortable as possible. Do you have any trouble sleeping? Come over and post in the back and neck forum, that's where I usually post and we can talk some more.
Thank you for your question. Although without being able to examine you I can not offer you the specific advice on diagnosis and treatment that you need, but I would try to provide you some relevant information about your health concern.
I think your symptoms may be due to nerve irritation in the cervical (neck) spine because of cervical disc bulge. This pain may be referred and perceived as occurring in the back of head & shoulders (as electric sensation)- LHERMITTES SIGN, arms or chest, rather than just the neck. Other symptoms may include vertigo, nausea (dizziness) and stiffness. It will be best that you consult a neurologist who would like to prescribe Pain killers, steroid and muscle relaxants. Other treatments could be cervical orthosis such as a soft cervical collar or stiffer neck brace to restrict neck movement till you get complete recovery. In addition, cervical traction may also be suggested by the doctor, if condition is severe. Hope this helps.