I am a Virgo and therefore a perfectionist by nature, so I understand where you are coming from. That said, I quilt because I love it, and I have learned over the years that nobody is perfect, so I give myself some slack on being "perfect". Pressing seams to one side on one row and the opposite in the next row usually gives me good results. I haven't tried it, but I saw a quilting tutorial where a pin was placed straight up, making sure it went 1/4" on both sides, then pins placed on either side to stabilize the piecing and that seemed to work. The Amish deliberately leave a mistake in their quilts, as only God is perfect. Fortunately for me, I never have to deliberately leave a mistake. LOL. Just be patient with yourself, perhaps basting just the place where pieces come together, then checking and if all is well, sew with a regular stitch.