My wife bought some blood sugar monitor testing sticks. Tested every morning upon waking and have had consistent readings of between 6 and 6.5 mmol...
Stop worrying. I was diagnosed with Type 2 over 30 years ago - it runs in male line of our family. With a healthy life-style and modern medication it's easily controlled.
Re heart attacks: the way it works is that cholesterol & blood glucose form gunge that gathers in the coronary arteries over the years until eventually the internal diameter of one of them becomes inadequate, and the bit of heart muscle it should feed gets starved of O
2 and starts to grumble. If nothing is done it starts to hurt and if flow isn't restored, dies, leaving you with reduced heart function. If it's a big artery that gets blocked you die.
The thing is, this very, very rarely just happens out of the blue. You get grumbling chest pains well in advance: in my case I found that after two large coffees there was a niggling pain as if someone were pressing the blunt end of a pencil outwards against my rib cage. Other people find that they feel pain after walking up a hill in very cold weather. In other words, anything that constricts your blood vessels will show it up. That's the signal that something needs investigation.
But there's more. As a bike-riding diabetic, your GP should send to a cardiologist once a year, who'll do a bunch of tests including putting you on a stationary bike and making you pedal
until you croak under successively higher loads while he watches your ECG on a screen. He can spot the signatures of starved cardiac muscle even before you feel any pain. If he does, further investigation can result in a stent (wire cage that expands the afflicted artery) being inserted by arterial catheter. Once the wound left at the insertion point has healed, you're back on the bike.
Only in the worst cases, i.e. if you shrug off the grumbles for too long, do you risk a heart attack and a possible bypass.
OK. After my coffee incident, 12 years ago, I had a major artery stented. I was back doing >100k rides in a couple of months and doing cols in the Vosges a month after that. Since then I've done several SR series, PBP once and a couple of diagonales, which are 1000+ km Audax-style rides across France. My lifestyle not being what it should be I've had two small run-ins since, both of which dealt with swiftly with stents, a dressing-down, and three weeks off.
So: you've got decades of normal life (plus pills) ahead. With proper surveillance you need never have a heart attack. Get to your GP, tell your tale, and don't worry.
ETA: A chum of mine has 5 stents and still does >100k rides with >1000 metres of climbing.