Hi
You seem to have sprained your neck.
If the pain is not spreading upto your arms or forearms, there is probably nothing much to worry.
Try the following:
*Apply hot water bag 10 minutes twice a day
OR
Apply ice 5-6 times a day (whatever gives you more relief)
*Tab Ace Proxyvon (1 tablet after lunch and 1 tablet after dinner for 5 days) (if you are not allergic to it)
*Avoid using a pillow
*Avoid keeping your phone near your body. Whenever you use it, keep it away from the body so that you don't bend your neck while doing so.
*Avoid keeping the laptop over the lap and using it. Keep it on a table over a couple of books, sit in front of the table on a chair and then use it.
Next Steps
Follow the above steps and do let me know if you have pain relief after 1 week.