Hi Cheryl,
I feel your pain.
It wasn't until I stumbled across the Glycemic Index a few years back that I understood why some of my favourite things just didn't act as they should. I know most people think us Brits eat nothing but bacon and eggs for breakfast before throwing another corgie on the fire to keep the manor warm whilst we're off shooting grouse for lunch.
However, I love Kellogs Corn Flakes. Like most Brits

Due to the power of suggestion, I would be unable to resist some right now if I had any in the house. Which is why I don't have any in the house.
When I was first diagnosed 11 years back it was an entirely acceptable thing to eat (according to the nutritionist I saw at the time), yet they used to habitually make me ill. Raging high unless you injected enough to kill a horse, followed by a crashing low a couple of hours later. Once I learned about GI, it made sense as they are up there with glucose drinks. Bagels are not far behind. Not that it will make you feel better, but bagels do me in as well and I also really like them. Lots of carbs wedged into a small space that absorb at a rate similar to rice with sweet and sour sauce. Amongst the worst GI and GL of any bakery product.
I just eat them once in a while and accept that I'll be high. IMO, it really is not making yourself that upset over provided you do the right thing the rest of the time.
If you like them savoury, you could make some really chunky home made humous and pile that onto the bagels; in theory, it should slow the release down a bit. Obviously you'll have to count the carbs in the humous as well, but it might help that post-bagel spike (or PBS as I shall now call it

)
Sorry if I'm preaching to the converted about GI and GL. A factor worth considering if you haven't.
Gary