A loss of 7 buy-ins in 2000 hands is a little excessive if you are a long-term winner.
Here are some simulations from the infamous variance simulator, using a typical TAG with a long-term winrate of 5bb/100.

On one run of the 50, there is a 6 buy-in loss after 1000 hands, and there are several simulations that finish close to 4 buy-ins down, but none any worse than that.

If your winrate is closer to 2 or 3bb/100, then losing 7 BIs in 2000 hands is more probable, especially if you play an aggressive "high variance" style featuring lots of big semi-bluffs.

Put your numbers into the tool at http://www.evplusplus.com/poker_tool...nce_simulator/ to see the sort of expected variance you might have over larger samples.