Minecraft keeps lagging, graphic settings on lowest possible?

I have my smooth lighting set to minimum, my render distance at 6 chunks, my max framerate set to 50 FPS, entity shadows, clouds, and particles all turned off… I've done literally everything I can to reduce lag, and I'm still stuck at 0-10 FPS. What's going on? I have nothing else open, except for one YouTube tab which I'm watching a video on. I've never had an issue with watching YouTube and playing Minecraft at the same time, so I don't think that s what's causing it.
Maybe it's the four enchanted things in my hotbar?

Framerate should be 30fps. The human eye can't really see more than that anyways.
my best guess is that your video card's drivers got updated by Windows. Windows' drivers are the worst. You should always use drivers from your computer manufacturer (or video card manufacturer). Try downloading them, uninstalling the old and installing the manufacturer drivers.
also, if you want best results… Your computer can only handle so much video without a dedicated video card. Playing video and video games pushes your video processing hard.
it doesn't matter that your computer used to be able to do it. Computers don't get faster than the first day you bought it, only slower, for a variety of reasons that are irreversible.
if it's a desktop, get a new video card. If it's a laptop, you need a better one. One made for gaming…

Download I think it's called Optifine. Also keep your PC cool or it'll slow you down.