Bread is around 60% carb by weight - doesn't really matter what sort of bread. I'd excpect to see that sort of rise myself if I ate toast - readings like that tell me that my system can't handle the carbs in whatever it was I ate.
The after-food test is supposed to be no higher than 7.8 and not more than 2 higher than your starting level. I guess your readings don't fit either of those criteria. My advice, if you don't want those sorts of BG levels, is not to eat bread or toast. If you're
making yourself eat toast, it should be easier to substitute something else - cheese and ham, maybe?
I do use a low carb bread that I get from a firm called SRSLY low-carb - here's a link. It's expensive compared to carby bread but for me it was either this or nothing.
https://seriouslylowcarb.com/
I buy the rolls which have less than 3g carb each.