For Minecraft Java, whenever I play, I use a few mods that i have that improve game performance, sodium, modernfix, and iris. However the rules say that fabric API is not allowed, but fabric cant load without it. my game is super laggy and slow if i dont have them in and it is essentially unplayable. Will my run still count if I do use those mods using the fabric loader?

Sodium, Lithium, and some others are allowed I believe, Iris, I don't think so, they also don't require Fabric API, but if you want to be on the safe side, check the Mod List, they have one for each version, check which version you'll be doing your run in and download the mods like from Modrinth, some aren't in Modrinth but you can also download them directly from the list: https://mods.tildejustin.dev/?version=1.16.1&run=ssg&os=windows