My heart currently is at 100bpm i've been diagnosed with a anxiety disorder my dr suggested to take a quarter propranolol if my heart goes to 100bpm, i have a healthy heart and im not frightened by the fast heart beat anymore should i still take it?

You can try breathing exercises or carotid massage to try and decrease HR. If that doesn’t work, I would take the propranolol as prescribed. Propranolol can have some anxiolytic effects by slowing heart rate. I would continue to monitor your HR and BP. 100 bpm isn’t terribly elevated, but as a resting HR, could become problematic in the long run and prolonged elevated HR can lead to heart failure.