Strange Lag!?

[danwald92]

So, I have a Forge 1.7.10 Server running on my LAN. 

8 Cores 2.4Ghz Xeon, 8GB RAM, Windows 7 x64 and Java 8.11 x64.

The server has bee running great for the last 2 weeks now all of a sudden I'm getting lag.

My Pings to the server are under 10ms and the server ticks are under 2ms. Anywhere from 2 - 5 players connected

The Lag starts with chests. A slight delay when opening them, consistently getting worse until unplayable.

Also, I'll be laying down blocks when all of a sudden they'll all disappear like I've rewinded half a minute. Movement is also like this. I'll be running for a while then suddenly pop back to where i was a minute ago.

 

Any Idea's? Help?