Void Glitch

I randomly started glitching and lagging, then suddenly ended up into the void, and nothing would load, I couldn't die, or move, or be kicked or banned. I have no clue why this is happening, as I was playing just fine the day before. I've tried everything that has helped other people, deleting my player data, re-installing my Minecraft, turning up my render distance, restarting my PC. I even turned off Opti-fine, but nothing's working, and I don't know what will fix it. Please help me.