Leak from top of fill valve?

water is leaking from the top of that black thing. i highlighted in red the rod, right under which is where the water appears to be coming from. the toilet is flushing fine, but refilling takes 10minutes. wasnt like this before. it is also making a whistling type noise when refilling, but everything i read says that only happens with the old float ball design, and this toilet has a overflow valve

Fluidmaster sells a replacement washer that may fix this. Sounds like you may have some debris caught inside. A new gasket washer is cheap, and worth trying.

so should i just buy a replacement top thing of the fill valve? I don't know what a gasket washer is. I took off the black top thing and when i made it fill with water, it sprayed everywhere. and i did the watercolor in the tank test, no leaks if that means anything

The gasket only costs a buck or so and is easy to replace. The instructions are on the card.