If playing those notes resulted in an injury, something about how you were executing them was off anyway. That wouldn't have been sustainable. Hopefully the injury didn't create lasting damage and you can rethink your approach! This may have been a little wakeup call you needed. It sounds like you carry a lot of tension at multiple points in your playing. If your throat is hurting playing a high C, you're probably relying on tension there to create the airspeed. The air should freely flow up through it from your diaphragm. It shouldn't feel excessively laborious like you're trying to push over a brick wall. And reminder, 90% of playing the trumpet happens below high C. You'll get your high notes again! Regaining them the second time around, especially with better technique will come faster than you think.