My server just randomly closes overnight

I leave my server on overnight to AFK for resources. It usually stays on for some time but when I wake up it has always closed. There is always a player online so this shouldn't happen but it still does everytime. I will add the log when it happens again tonight. Here is the log for when it crashed while i was at school: https://mclo.gs/0gosCDq

I would be grateful if someone had a solution.

Ah okay I think I attached the log for once I started the server back up again. Tonight I will get the log before doing this and attach it. But if lag built up that quick, and is continuing to build (having just looked at it), is it likely to be the issue?