get well, recover
瘉 centers on recovery from illness or injury: getting well and returning to health.
瘉 combines 疒 (sickness) with 俞, which likely contributes the sound and may relate to the idea of improvement or passing through illness.
The sickness enclosure 疒 surrounds 俞, like an illness being contained and then overcome. Picture a patient inside a healing ward, steadily getting well.
For ユ, imagine a doctor saying 'you' are recovering: you -> ユ, and the sickness inside 瘉 is fading as you get well.