[zizazziza]

How is there a raise from CO and you call from CO. Where are you in this hand and who is raising?
Do you know how the good players view you? I mean I think this is key. He made a .5psb so this could be a A2 bet or something like that. They only have $300 at the beginning of the hand.
So we have $300 - 45 = $265 left for CO and $265 left for btn if he calls.
If you call and btn folds there is $110 in the pot. If btn calls there is $140 in the pot. Other than a spade, there is no real turn card that would scare you (assuming the btn calls behind).
Either way, you can bet out on the turn and get it all in easily by the river. I think that assuming you are not an aggressive player, that this is a pull instead of a push.
(this all assumes you have position on him, but I dont understand who is where in the hand. Also, is this is a full table?)