Kindness should not require an audience to feel real.

If a kind act only appeals when someone is watching, the thing driving it is not kindness. That does not make you a bad person; it makes you a normal one, and it is worth noticing so that the audience stops being the deciding factor.

Run the test occasionally. Would I still do this if nobody ever knew. When the answer is no, you have learned something, and you can still choose to do it anyway, which is how the habit gets built.