The most important thing to remember is not to panic. It is most unlikely that there is anything serious to worry about. Remember that you will get better. Like symptoms of a cold, you may have pain and discomfort for a few days, but it will go away.
If recommended by your GP/ Pharmacist, use over the counter paracetamol or ibuprofen for a day or two to help you manage the pain. You can use a heat pack or hot water bottle if that gives you relief. Continue to keep moving as much as possible. Walking is the best remedy.
When you feel pain, this is not a sign of things getting worse. It is just the sensitised soft tissue getting simulated. This is very similar to pushing on a bruise- it hurts, but it’s not going to get any worse.
Finally, remember to breathe from your diaphragm. Holding your breath can increase the pressure through your sensitised soft tissues which lead to more pain.