Unexplained Lag

I noticed that Minecraft was lagging yesterday and my fps were very low, but other games were running smoothly. I updated my drivers, I changed the runtime parameter, I lowered every video option in the game and I deleted java and Minecraft 3 times and I reinstalled them. Also, I noticed when the launcher starts the task manager says that CPU is 100% only for Minecraft. Still, nothing happened I need your help.