Relax! Your quilt doesn't look that bad! I think very often we are our own worst critic. If you want a accurate 1/4, may I suggest a 1/4inch foot with guide presser foot for your sewing machine. I think you can find one for most sewing machines. When you are sewing, you have the fabric up against the guide,Presto! Perfect 1/4 seams the easy way.As far as sewing triangles goes, have you ever considered the Wonder Ruler? You make a tube and then use the ruler to cut out a perfect ruler. I think the Missouri Star Quilt co has a video on using a regular ruler to achieve the same results. As with anything you do in life, practice makes perfect. Good Luck!