You told me that the server nulls & only newly created accs could login, which was the deadlock in most PI servers.
Not once did you say it was this issue, and this has been explained you have a memory leak, getting a VPS might delay the occurrence by a few hours, but you will still get this error eventually, as its eating your available Memory.
I told you when i helped you that, its a terrible base to use & needs a lot of work before it even gets to a useable state.
Edit: Allocate more Memory to the server..
Change Xmx value to a higher value in your run.bat, or better yet delete it.