Firstly thank you for giving us a detailed history about your problem. It is important for us to know the detailed history before coming to any conclusion. Sensitivity can be due to wear of tooth because of excessive biting pressure, hard brushing, cavity, abrasion. I suggest you to visit your dentist and get full mouth x-ray and do a sensitivity test. This will help you to locate the tooth which is sensitive.

Hello sir. I would suggest you to get a Full mouth XRAY taken to find out any hidden decay whether present or not which cannot be visible only by clinical examination.

Go for opg xray there might be some cavities

Take few more opinions from dentists. There may be interdental caries or may be attrision. Take a x ray if suggested by dentist.

Use sensodyne rapid relief on that side and leave in for 16 minutes before brushing off. It will give you symptomatic relief. Visit a dentist for a thorough check up along with x ray. At times, there can be hidden cavities that are seen on x rays only. Incase all ok on x ray, it could be due to worn enamel, eroded enamel close to gums, or similar reasons. Hope this helps

For now it’s ok to take toothpaste for sensitivity but won’t help in long run if you are having sensitivity to hot as well

Cervical abrasion may be in one of your teeth or it may be microcrack in one of your teeth while chewing hard food.