I feel my angina is getting worse (seem to get pain more quickly on exertion). I also have a hiatus hernia. So one symptom could be masking the other.

Dont ignore angina. Unstable angina is very treatable. Contact cardiologist stat.
Paraesophageal. Your hiatal hernia is probably only likely to mask your symptoms of angina if it is very large, also known as a paraesophageal hernia. This is best diagnosed with an upper G.I. Contrast study.