Treat it like poker and figure out a smart way to manage your BR. I don't know anything about sports betting, but set some rules for yourself like any single bet can't be more than x% of your BR. Then decide how much you should withdraw and when so you know even if you have a losing streak you're still making money.
I think this hits it for ya.. You should have limits just like a poker BRM. Sounds like you get VERY GREEDY!! Looking for that BIG win but betting WAY TOO Much!! Can you really justify betting 6500 on any game/games?
Failing to Prepare is Preparing to fail : John Wooden