Reasons:
1. You may be on tilt.
2. You may be a losing player.
2. You may be counting "pots" as "dollars". You will win far fewer pots than you will lose, but those pots will be large and make up for the bets you put into losing pots.

I'm not sure how many BB 1k is to you, but it's possible that you are playing too long when you are losing.

Without more information, it's hard to say.