That's really weird, I eat a lot of bananas too. A lot of fruit and veggies in general, I would think since you're eating healthy and not just downing empty calories that it would be fine. Maybe just start eating everything in moderation? I know I always check the back of the box of whatever I want to want to eat/buy for ingredients and sugar/sodium levels.
Fruits are good, but I was advised by my doctor to still eat them in moderation because they contain natural sugars that can raise your glucose levels.
Anything with carbs is going to spike your blood sugar. If your trying to stabilize blood sugar, I would recommend eating lots of protein and vegetables. As for carbs, choose the healthy carbs or brown rice and more slow digesting carbs. That way your blood sugar won't rise as high or fast.
I'm type 1 diabetic and pregnant, so u have been testing blood sugar like crazy for a good amount of my life.