Bad reaction to sugar

I’m 19 years old, female, 5’10” and fluctuate between 125 and 128 ish pounds, take no medication, only vitamin D pills because I had a deficiency a year ago So I think I am generally healthy, but a lot of times when I eat too much sugar at once I get like a sugar crash, which I know is normal But I feel like very sick, sleepy, nauseous, my heart will race, I breathe heavier, sometimes I feel hot but not always, and I’ve thrown up from this before, and one time I had trouble focusing my eyes but that hasn’t happened again. And I know the obvious solution is to just eat less sugar, to avoid this happening. But here’s some examples of when it’s happened: \-At a restaurant after some fries, an aperol spritz, and a creme brulee \-After work when I first ate some m&m’s as a snack and then greek yogurt with granola, and some juice \-Watching a movie and eating a bigger amount of m&m’s in one sitting And I get these aren’t healthy things but I feel like a person should be able to eat these things like that occasionally and not get a reaction like that? I’ve worried I had diabetes before, also because about a year ago, maybe a year and half, I weighed a lot more, like closer to 140 pounds, and I never tried to lose weight, it just happened, there were appetite changes as well but I still felt like I ate normally. But then when I got my blood tested they only found the vitamin D and folic acid deficiency, and after treating that my weight only went up a tiny bit so I don’t think that was the cause of it. I don’t mind the weight I am now, but if it’s because I’m diabetic or something else then I don’t like that, but I’m really scared to go to the doctor because I know I’ll have to get my blood drawn again and I have had a bad medical phobia since I was a child, getting my blood drawn last year already went terrible So what could this be and what do I do?