It sounds like you're experiencing performance degradation in Minecraft, which could be caused by several factors. Here are some common causes and their respective solutions:
Possible Causes and Fixes
1. System Overload or Resource Usage
Cause: Other applications or processes on your computer may be consuming a lot of resources (CPU, RAM, or Disk).
Solution:
Close unnecessary background applications.
Open Task Manager (Ctrl + Shift + Esc on Windows) or Activity Monitor (Mac) to monitor resource usage.
Check if any program is using an unusually high amount of CPU or RAM.
2. Outdated Java Version
Cause: Minecraft relies on Java (for the Java Edition), and an outdated version can cause lag.
Solution:
Update Java to the latest version from the official website.
If you use a launcher like the official Minecraft Launcher, ensure Java is managed through it.