Some medical practices or hospitals have support groups where patients can gather to discuss in person their situations. Check out the resources available in your area, or online and get involved. You’ll be better for it, and probably help someone else experiencing the same feelings as you have.
Support groups on social media may also be helpful, as long as one understands the advice dispensed in these non-medical groups should never be confused with the advice from your doctor. Sharing with other people with heart conditions on social media can be very helpful in reducing anxiety while realizing that others may be experiencing similar feelings as you.
As always, please consult your physician, cardiologist, or other qualified health providers with any questions you may have regarding your mental or physical health.