I understand your concern.
Well as describe there may be following possibilties in your case-
Benign chest wall pain - a transient and fleeting irritation of the pleura, the slippery membrane that lines and protects the lungs.
Panic attack -an episode of incredibly intense fear or apprehension that is of sudden onset which include symptoms like chest pain, shortness of breath ,etc that mimic with symptoms of heart attack.
At your age, it is less likely to have any cardiac pathology.
You should try some self care measures like
Hydrate yourself with plenty of fluids.
Avoid alcohol,carbonated beverages,spicy,fried foods.
You should take short breaks of rest while doing work on computer,mobile.
Also do gentle massage on back of neck with muscle relaxant ointment and apply warm compresses with a heating pad.
Take OTC Prilosec and Motrin.
Do steam inhalation and saline gargles.
Physical therapy can be effective in your case.
Do neck stretching and strengthening exercises.
If symptoms'll persist then see your doctor again.
Hope this helps.
Use reply to let me know if you have further queries.
Please to not forget a positive rating and avoid poor/bad rating.
Bonus is highly appreciated.
We are here to help you until you satisfy.