How bad are occasional spikes?

I’ve been doing fairly well managing gd with diet and exercise, but I got a really high reading tonight after stupidly eating cake (182). Usually a small sweet after a protein rich dinner won’t spike me like this, so I thought I would be ok. Two hours after I was still 174, and now I’m officially freaking out that it’s not coming down quickly enough. With that being said, how detrimental is the occasional spike? The internet doesn’t provide much of an answer except just overall how bad uncontrolled GD can be for the baby. Also I think I’m done with non sugar free sweets 😬