Your symptoms of pain, headache and nausea etc are suggestive of spondylosis. This causes compression of the spinal nerves in the cervical spine region. You have to discuss the best treatment option with a neurologist, which can range from medication to physiotherapy to traction, cervical collars or even surgery. Alternatively you can visit a chiropractor or a physical therapist and learn some exercises which you can do to relieve the compression, but consulting a neurologist is a must.
Use a hard bed to sleep. Avoid a pillow. Roll a towel and place it under your neck while sleeping on the back and between head and shoulder when lying on the side. Initially this will be uncomfortable but with time the acupressure will work. Use an analgesic cream or spray. Anti-inflammatory drugs help. Also, you must improve your posture while sitting and working. An occupational therapist can help you with that. Take care!
HI DR Kokil thank you very much for your help hendo160