2nd neck adjustment this week. Sore, slight headache. Tightness and stiffness, especially when moving neck. Neck “clicks” when moving head side to side. How can I relieve this or will it fade away on its own?

Although there is a. role for adjustment there may be something more serious causing your symptoms. It would be a good idea to seek a second opinion from a traditional western medicine health care provider. You may need more sophisticated testing such as an MRI in order to make an accurate diagnosis and then receive the appropriate therapy.
Spinal manipulation. Spinal manipulation is generally very safe. Rarely does "clicks" in the neck mean that there is something wrong If you have numbness, change in speech, weakness, or dizziness go to the ED. Headaches can occur after manipulation and often resolves. Most traditional medical doctors have no clue about the benefits of safe spinal manipulation . See your doctor in person for a firm answer.