Nice colors. Suggest cropping the top to have as much space above the flowers as below the vase. I would also leave out the dado rail which does not contribute. I would intensify light and shadow a bit. Try not to have the vase dead centre, perhaps a small metal object beside the vase?
Dip in hair gel and shape bristles with your fingers. Should later dissolve in brush dip. If this is meant to be a filbert I would reshape the bristles with a razor. If the brush is a round, then the gel will do the trick.
Alternately, a coat of brush dip and an elastic band may bring them back into line.
Push some pins or small nails through cork, plastic or rubber rounds. Place painting face down on pins at corners in a clean out of the way place. Or lean against a wall, face in with pin spacers. A double pin cork device can be used to stack multiple wet canvases for transport by binding with a luggage strap.