Massive night of drinking - is this normal?

I would say it is normal in that context. It is also possible you are getting the flu because your bodies immune system was out of whack for a while, so that could be part of where you are at now (i.e. hangover turning into a flu/cold)

Yes, totally normal to be really sick for a full day after a night pounding shots. I love tequila so I know believe me. I don't vomit tho but a lot of people do. If you don't really handle hard drinking like that you might want to ease up a bit tho. Let her do the shots and you just stick with the beer or mixed drinks that you prefer. People I go out with rarely keep up with me in shots but I don't want them to get sick so I don't push them

You have alcohol poisoning.

This could last a few days.

Don’t do that again!

Yeah that's normal. You're in your late 20s and she's in her early 20s you guys are at opposite ends of the spectrum and alcohol does throw a person's body off for three days after a night of drinking so its really not weird that you still feel off a few days later. Your body is trying to get its processes back to normal. Next time you're hungover or even just sick take sips of water and go slow drinking it. If you chug it then it comes right back up.

Yes this is normal.

Your friend is an alcoholic.

Kind of weird you're still feeling it five days later, but yeah, alcohol overdose can screw you up. It's poison.

Learn to know your limits.