35 hours of playing 8-tables I suppose. Thats like 4 work days. And down only 5 buyins. It doesn't say much. Except that you don't have too much time to play.

As celtic said, it might be just your biggest losing hands postflop. Maybe you just fucked up big there or simply had a bad run.

And one other very important thing. You are learning. Don't play too much tables. Find the right number. It could be 4-6-8-10. Whatever, just make sure you can track all the tables and spot whenever ANYONE does anything funny or out of the line. Because that is very profitable.
For example, I spotted a reg (while 4 tabling) opening waaay more from UTG then from other positions. So on occasion, if the coast is clear and my hand is playable (more or less ), I 3bet this guy from CO or BTN. Those things you can't spot while mass tabling, and they still give you those crucial few bb of profit every now and then.