JAVA HEAP SPACE but yesterday all was fine

Check if this post helps, seems some people are reporting issues with VS code extension. It can also be a rule not just a binding that can cause this, so it helps to uninstall different parts of openHab to test with and watch what is happening with the heap size which can be watched with the system info binding.

openHAB 3 runs out of memory / java heap space errors, CPU 100%+ after a few hours - Setup, Configuration and Use / Installation - openHAB Community