How Can Anxiety And Palpitations Be Treated?

Hello! I am a 30 year old woman diagnosed with mild mitral insufficiency. I experience alot of anxiety, palpitations and I cannot exercise without feeling bad afterwards and my heart pounding for hours. I am very scared of my condition. I am on a low dose of metoprolol, been on it for 5 years almost. 25 mg of Egilok/day. I also take magnesium, eat healthy, no smoking or drinking. My bp is good also. My question is, what to do about my palps and not being able to excersise? I have developped agoraphobia because of the skipped beats, I cannot go out alone without feeling short of breath and my HR spiking. Thank you!