A bit of advice regarding your attempt to buy at $4.50. At that time it was fairly evident that there was substantial support (relative to volume) at $4.50. For some reason most investors psychologically like to buy or sell at even numbers. Especially at .50 & 1.00 points.
So when you really want to buy it's often wise to put an order in for .01, .02, or .03 above the level of support. In this case if you had put in an order at $4.53 it's most likely you would have been able to get all or at least most of your order filled at $4.51, $4.52, and $4.53. Since you correctly saw strong support at $4.50 there wasn't a lot of risk buying at those prices.
Regarding your message at the close yesterday, if you had looked at share availability after hours you would have seen a block for sale of 18,300 at $4.60. That would have been a good opportunity to fill your entire order at that price. Right now it looks like there is at least 4,000 shares available at $4.60 and there is a bit of support at $4.59 so you might want to put your order in for $4.62 and you might pick up all or most of your shares at that price or less.