Hummingbird, keep doing nice things, as I am sure you will, because it helps make the world better in ways we may not even realize.
There may be a plethora of reasons someone does not acknowledge your thoughtfulness such as they are enjoying the good feeling as a break from the usual stress, and they forgot to show appreciation.
I would just add a piece of advice that I tell myself (when we are on speaking terms), which I read in Pirkei Avos. I am not wording it exactly, and I have to work on being more careful about not just remembering the concept, but also the exact wording. But it went like, “Dont do the good deed for the sake of the reward. Do the good deed ‘not’ for the sake of the reward. (Maybe someone can polish the wording up).
Continue doing what you are doing and know you are doing good things and Hashem is appreciative.