Your treshholds are low. My fasting was below 95 And after meals 120. I wasn’t on insulin just diet controlled. I limited carbs and made sure to eat some protein. Fruit with peanut butter helped keep my fasting numbers low. I never had a fasting number below 80. Sorry I can’t offer tips. 😞
Oh and you most certainly are not failing him!!
Cut carbs and go on walks after every meal (even if just round the house). Look into myo-inositol also, it's natural and really helps with bringing sugars down.