@MariaAragon64 Continue! Some of the best paintings come from artists who aren't or were never satisfied with their progress on their artwork. My brother isn't famous, but an excellent artist; he still discards drawings & paintings because "I don't like the way I made the nose(or other parts) look".
Walk away as someone suggested. If still not satisfied with your work, start another if you can. By working on another, he'd realize what he could do to the 1st to make it what he envisioned