Good job, Joe! As for it being a bit off size - check to make sure your fabric is cut right - just one skinny width of the ruler line would be enough to make it smaller than planned. Also, double check your 1/4" seam allowance - just a smidge over 1/4" can make you run short - and put both those together (cutting & sewing) can make a difference too!
But it really does look great - and frame it - as previously mentioned - and hang it by your sewing machine - for inspiration when frustration tries to get the better of you!!