Minecraft running choppily/performing badly

Hello. While playing, I am encountering multiple recurring and frustrating issues. First, when creating a new survival singleplayer world, the title screen will occasionally show, before I spawn in, which usually takes up to two minutes. Then, upon attempting to get wood, the blocks will break, not yield their drops, and reappear, as if not mined. When I do succeed in breaking the block, the item itself takes 10 to 20 seconds to be picked up. Lastly, the entire game will periodically "freeze", in which I can move, but nothing in the world can happen (killing mobs, mining blocks), until finally mobs begin to whiz by at light speed for a second, and the world returns to normal.

To reproduce this, one only needs to try playing a survival world. I have already tried multiple fixes, including changing the video settings.