Since you want to refuse, don't be tactful, but euphemism can easily lead to unnecessary misunderstanding ... As for your guilt, refusing others is your basic right to communicate with others. Since it is a right, there is nothing to feel guilty about, perhaps because the number of rejections is too small, so I get used to it. One more thing, even this will cause guilt, and there are too many things to feel guilty about. Conversely, others will reject you, won't they? In the same way, more importantly, slowly make yourself strong, neither forcing others to do things, nor over-reflecting, be a meaningless bad person, and don't care too much about what others think of you, which will affect your principle of doing things … people who take our own path and treat us as friends will not be too embarrassed to embarrass us …