Even if you don’t have hip pain during or after exercise, strong, flexible hips are vital to running and good overall health. Weakness or tightness in the hips have been linked to injury elsewhere, including runner’s knee and Achilles tendinitis. People who are sedentary for most of the day, such as sitting in front of a computer for several hours at a time, tend to have shortened hip flexors. When your hip flexors aren’t able to function properly, your running form is compromised, and you’re more likely to have one of the types of injury described above.
Two possibilities to mention:
1. If your skin is tender to touch and burning is not affected by body movements and different positions, then it can be shingles (Herpes zoster virus reactivation in one of the spinal nerves). Nausea can be also from shingles. This causes burning pain going like a stripe from the spine to the front. Often (but not always) rash appears after some time. Neurologist would tell you, if there is any available painkiler for your situation.
2. Bulging or herniated disc or some other disorder in your thoracic spine (osteoporosis, arthritis..) could cause pinched spinal nerve. This type of pain would be affected by different body positions and would not be tender to the slight touch. Again, neurologist could say more.