I would be happy with your block. The fabric is beautiful.
Have you tried the sew then cut method for hlf square triangles? Cut your squares 1 inch bigger than the finished size you need. Mark a diagonal line on the back of one of the squares. Place the two squares right sides together and sew 1/4 inch from your marked line on EACH side. Cut on the marked line. You will now have 2 half square triangle blocks you can trim to the perfect finished size.