A candle loses nothing lighting another, but it still needs protection from the wind.

Giving does not diminish you, and that is genuinely true. But it comes with a second half that gets left out, which is that the source still needs tending. Someone giving continuously in harsh conditions goes out, and then nothing gets lit at all.

Alongside whatever you give, ask what protects you. Sleep, distance from certain people, time that belongs to nobody. Guarding the flame is not selfishness, it is the condition for continuing.