With self-portraits at f/2–f/2.2, tiny position changes can throw focus off, so consistency matters most.

Useful techniques:

• Stop down a little, such as f/2.8–f/3.2, and move farther from the background. You’ll still get blur, but it’s much easier to keep your whole face sharp.
• If possible, trigger autofocus while you’re already in your final pose using a cable release or remote. Focusing on a stand-in object is often not accurate enough at very shallow depth of field.
• Use a single AF point, ideally one that covers the eye. Check the camera’s focus-point display on playback/live view if available.
• Mark exactly where you’ll stand or sit, and keep your body and head orientation consistent each shot. Pick reference objects to aim your body/head toward.
• If your camera offers face detection in live view, try it.
• For setup/testing, place a target where your face will be (even a printed scale or chart angled about 45°) to verify where focus is actually landing.

In short: reduce the difficulty slightly with a smaller aperture, focus from your real shooting position, and make your pose repeatable.