Not saying you have anxiety but...
Merepage, anxiety can be insidious (sly in its effect) and it can come from a subconscious fear of failure or a fear of some unknown future misfortune (losing a well paying job) such as you wrote ("I continue to raise 4 boys, I love life, we are financially stable, good husband, and continue to work selling medical software for 25 years. I seriously have no reason to worry about anything."). It happens often to those who are well off (financially), seemingly happy, feel as though they have a good marriage and their children are achieving their goals. Great, things couldn't be better! But, sometimes it can be anxiety (nagging the subconscious) with the "This is too good to be true... something is gonna happen... I just know it." And... it does... it shows up as physical symptoms.
You also wrote, ("I doubt I could get away with that for almost 3 yrs with severe anxiety etc.") Oh yea, anxiety can plague a person for years and for some for a life time if untreated.
Ok, no one but a doctor would know if your symptoms are anxiety related. Don't be reluctant to talk to a doctor about it. There is no shame or disgrace dealing with anxiety. Have a doctor scratch anxiety denial off the list. Hey, it's vogue today, many successful people have a "Therapist."