Can Small Vessel Disease cause a heart attack?

[Winded67]

I am a 50 year-old man that has had increasing issues with angina over the past 5 years. Episodes were initially very infrequent and brought on by stress.I had a normal treadmill stress test and a normal cardiac cath. Doctor said my blood vessels were very clean. Episodes increased in frequency and severity. Last year I had another normal tread mill stress test and a normal CT angiogram. Now my chest pain is brought on with exertion, stress and at rest. It wakes me at night. Aggravated by laying flat or drinking cold liquids. It is usually relieved with 1-2, sometimes 3 sublingual nitro, but rarely goes away completely. It varies in quality from sharp pain to pressure in multiple spots in my left chest, neck, shoulder and arm. Sometimes it is under my left scapula. Other than the nitro I am on 10mg of Amlodipine (for about a week) and 1,000 mg of L-Arginine (which I read is good for small vessel disease). I have not been told I am have small vessel disease, but am operating under that assumption. My chest pain has gotten worse and I am profoundly short of breath since increasing the Amlodipine from 5mg to 10mg. My Cardiologist is very disinterested in pursuing this. He has not come out and called me a liar, but treats me like I am making things up.
Is it safe for me just to live this way? Can I go about my life as best I can consuming nitro like tic-tacs? If it is small vessel disease is it just a chronic, incurable condition that I need to accept? Can I exercise safely?
Thank you.