Lactose intolerant?

I’m 20 and never had issue with lactose and stuff or dairy but the past couple of months I can’t eat eggs without having a bad reaction and yesturday I ate ice cream and cant get off the toilet... is this something you can develop out of nowhere? I’m allergic to wheat, I don’t know if that holds any relevance since it’s not an intolerance, it’s an allergy but I wasn’t sure if it made it more likely?