That ping plot sample looks fine. Did you do it when the ping was high in the game?
Also note, the ping varying wildly can be a sign the CPU is being taken away from the game for short periods of time. Check the CPU usage in the Task Manager, under the "Processes" tab. When the game is not running, the CPU usage should almost always be at 0. If it is bouncing higher than that, then you may have found the culprit.
If your computer is running Windows 7, or later, you can also use the "Resource Monitor" to see even more information about what where your computer resources are being spent.
Packet loss is almost always an Internet related issue. Usually indicating a router in the path, between your computer and the server is having a difficult time managing its network load.
Please keep in mind, schools are starting back up in the U.S. and this ALWAYS causes a lot of Internet problems, for a while.