After I posted, I started thinking and wondered if there was a way to ease your discomfort from inconsiderate refusals. It does take courage to ask for money so I admire your willingness and effort.
Perhaps, it is possible to see the rude refusals of donation as evidence of inexperience or lack of skills on their part? It takes some experience and some training for them to respond graciously to a request, especially for more money. Easier said than done, I know.
You are doing an important job in soliciting funds and gaining valuable experience in doing so.