You are aware, I hope, that online mario Kart has hackers who can fire blue shells whenever they want? It sounds like this has happened to you. Here's a hint, if they do that, drop back to about 8th, get a good item, stay back until near the end then catch up to him without using the item and then use it to get over the finish line. Cheap tactics but hackers deserve it
The complaint "you get stunned for way too long whenever you get bumped or knocked into a wall" definitely makes it sound like the game is too hard for you.
If you get hit by a red shell, you are doing it wrong. Trail items behind you. Only drop/fire backwards when the next item is ready. If the next item is an upside down box wait until you're almost at some item boxes then fire both backwards.







