Hi Hibby65
Like you I had some success with a low carb diet then in 2012 had a heart attack.
I have now got my weight back down to acceptable levels and am in remission with a Mmol of 39.
My only problem is with cycling, I need a certain amount of carb intake to offset the massive calorie loss per ride. Sometimes just taking 30g of carbs per hour is enough, though I do take food with me in case of a mishap with the blood sugar dropping too low. Generally speaking a low carb diet has now become the norm and I have to accept this is part of my lifestyle, along with no alcohol or smoking. Lots of exercise and make everyday special.
You have been successful in the past so I wish you luck and a good heart to try again to treat your symptoms with some TLC.