Minecraft bends around funny?

Maybe you know what the mistake is:

If I hold down "w", I just jerk. So I run, stop, run, etc.

At space I jump and fly now and then again.

In addition, the chunks load incorrectly and the screen flickers more often.

Have MC already restarted several times.

Hope one knows it.

Thanks, but it was a game mistake. The rest went well and my PC also creates games with significantly higher graphics performance.

After a day it was gone and now it's back to normal.