Why do I get those weird colds/flus all the time ?

[EthanHunt1995]

I am a young adult (I am 20), in college, quite healthy overall except for a weird chronic illness since my childhood (at some point, I would start throw up all the time until I would have to be hospitalized because I would get dehydrated) that had been at the time diagnosed as migraines as the doctors couldn't find what was wrong with me as all the tests I had done were okay but that I know strongly think is Vomiting Cycle Syndrome as the symptoms and the triggers (noise, colds and chocolate) are exactly like mine. And that takes me to my colds. Whenever I get colds, I start having a very sore throat like it is full of mucus (sorry for the awful description) but that I cannot cure no matter what I try (drink a lot of water, take Excedrin or take Advil). Soon, the sore throat makes me feel very nauseous and I eventually start vomiting (sometimes only a few times but other times up to twenty times) until I can stop the vomiting (with medication or Coca Cola) and then I start at last sneezing and stuff like a real cold. When I was a kid, I would go through this in the winter without being too much bothered by this (missed school was not such a big problem then) but now that I am growing up, I very often miss great moments like vacation, birthdays and parties because of that. Worse is that my colds worsen in the summer (I can catch up to three colds per summer) because it seems to get triggered by being cold at the beach or in supermarkets with air conditioning. It is getting really upsetting and whenever I start having a sore throat or I spit mucus I can see that the three upcoming days will be ruined (as I won't get any better until the next day and then I will take a few more days to recover). Can anyone gives me help as to why my colds are so weird, what I could to help them or if there is anyone else like me ?