Your work looks exactly like 99.99% of the rest of ours when we started out. Here are my suggestions to combat those fears, and others have their way of doing things but this is how I get perfect seams and finished blocks. One key thing to remember: When doing piecework, a ruler is your best friend. I keep a 1x12, a small square, and a similar rectangle ruler near my machine at all times. Before doing the next seam when doing piecework, measure the seams against the finished size. For this pattern, sew 3 squares together, then measure the center square to make sure it is the size the pattern calls for. Do this for all 3 strips of the 3 squares sewn together. Then sew one strip of 3 squares to another. Now measure from the center points of where the 2 triangles meet out to the seam line. Is it exactly half of the total 'finished' size of the triangle square? If not, the seam line is off. When I sew strips together where I have to match up points, I first 'baste' with a longer stitch. Instead of 1.8 or 2, I use a 3.5. That way, if the measurement is off, I sew the seam again without taking out that 'basting' stitch (unless the edges of the strips don't line up which means that measurement is off.) Measure the seam and if correct, pull out the first seam and measure again. When it is correct, reduce the stitch length and sew on that basting line. If you sew a little off the line, simply turn over the fabric to the front and check for any stitches poking through. Turn it back over and carefully snip those stray stitches and pull through. Measure again when adding the third strip. When adding the frames to the squares, measure the strip widths (white sq with triangle sq), and then measure the square for finished size (triangle points to triangle points. Your next step is important for lining up: before adding the adjoining square, fold over the narrow sash (frame). Make marks where the 2 seams are on the 3-squared strip. Fold back over and pin the seams of the square to line up with those 2 marks you made. Put the pin directly into the seam holes. Take a ruler and place it along the seam lines and check if the seam lines up, and if the 2 horizontal strips of squares you just made are the finished size of the pattern. I hope this has made sense and once you get the hang of it, it will be second nature to use the rulers. Practice practice practice and you will amaze yourself.
P.S. You didn't post to have us point out any flaws, because there aren't any. You came for guidance and we are pretty good at that as we have all been there! And if it were me, I wouldn't take this apart or throw it away. Frame it for your sewing room wall. It will do wonders for your sewing self esteem. I have a wall full of stuff that shows me how far I have come. I think if you continue with these colors and patterns, you are going to have a beautiful wallhanging to show off!