Coumadin for mechanical heart valve?

I’m on Coumadin for the rest of my life. My blood is drawn once a week in the morning. I had a mechanical aortic valve installed in 2012 due to the natural aortic heart valve leaking giving me a murmur.
Since 2012 my cardiovascular surgeon has been monitoring my INR. A standard of blood thickness or thinning measurement. If my blood test shows a thick blood measurement it means I could easily form a clot anywhere including my brain then it could turn into a stroke. That’s the main concern.
The others are a heart attack or a clot getting stuck in my lung. If the blood is too thin I could “bleed out “. If my brain bleeds out it’s pretty much a fatal event.
I’m in danger of bleeding heavily from a simple shave. I develop bruising and an ER visit to lower my blood thinner.
They use a bag hanging over my head and it slowly drips vitamin K.
This vitamin lowers a high INR measurement to the point that makes my blood within a safe INR.
An INR around 1.0-2.0 is considered within range. My number was once beyond 12.0 meaning I had Coumadin poisoning. Way too much as 12.0 is the highest the labs go to. Right now I’m at 2.9. Slightly above range but not enough to get me into trouble. Has anyone have to live on Coumadin or warfarin (same thing). For life? I had my blood drawn yesterday morning but my cardiovascular surgeon has never returned my call. This is crucial because it determines which level of thinning or thickening of Coumadin in order to keep my levels within range.
I called him this morning and he didn’t respond which is highly unusual.
Should I wait until tomorrow and call him again if he hasn’t responded?
Sometimes I need to see my cardiovascular surgeon and I call and the phone rings once and she says “can you hold? And doesn’t give the chance to say yes or no. The call goes dead for the 20 minutes I waited, no music to indicate that I’m on hold or hung up on. This happened twice. I finally got a woman says “I’m either busy with another patient or I’m away from my desk. Then she puts me on voicemail and ask for an appointment because I need surgery soon and he needs his approval and/or instructions. Nobody ever called me back so I contacted my insurance provider and asked if they had a list of in-network cardiologist. As it was it took over 2 months for the appointment. But my insurance company called that office to have them call me witch they did right away. So the appointment was made but he’s not helping by faxing over his order.
I think I should switch cardiologist.