Hi, could try mixing proteins with the banana, I eat more peanut butter now than I used to because of this. Just make sure it’s a sugar and added fat free version. Aldi by far the cheapest. The protein slows the digestion, you could try testing if it works for you.
There’s some info online about using food combinations to manage glycemic load, rather than just using glycemic index. You could also try adding 10g of dry raw oats on top of your yogurt and fruit. For a big boost try adding a teaspoon of Ceylon cinnamon as well, over a few weeks that’ll bring down your overall levels. Worked for me really quickly. Ceylon cinnamon is less bitter. That’s the breakfast I have everyday, I alter the fruit but it’s always berries.
Good luck