How do I pray when I feel invisible, as if no one really sees me?

Say it exactly like that: no one sees me, and it hurts. Do not tidy it into gratitude first. The ache of being unseen is real, and naming it to God is not complaint but honesty. Then let one old claim be true even while you doubt it — that you are known, in detail, by One who was not fooled by your surface and did not look away. Ask, not to be noticed by everyone, but to feel, for one moment, seen by the One.

The psalm's own idea is that God is yodea — the One who knows: not a distant watcher, but a knowing so close it counted your sitting and your rising before you spoke a word.

From the sources “O Lord, You have searched me and known me.” — Psalm 139