With 2 collapsed arteries, is this a danger for my heart?

I am assuming you . Are talking about coronary artery disease in the form of an atheromatous plague occlusive disease. Also I am assuming you don't have a heart attack. If above is right, you are supposed to be under the care of a cardiologist now. Drug treatment, stress test, 2d echocardiogram, cardiac catheterization and evaluation for a possible revascularization procedure already possibly done.
Arteries. If you have two obstructed coronary arteries, that is certainly a significant potential impairment of heart function.