How do I tell people I'm only human?

This has been bothering me for a very long time. How do I get my so-called friends and family members to realize that I'm only human. What I am saying is that they can inundate me with their problems and their friends' problems (which range from everything to "I'm gay and I don't know how to tell my father" right up to "that wretched woman took my pants and re-stitched it without my consent" etc. But the minute I need that someone to be "there", they poof and disappear. This seems to be a common problem but why do people do this? The minute I am struggle with internal problems like my sexuality or a nasty employer or a backstabbing friend of the family...those around me generally respond with "you're not supposed to have feelings." So my question is: how do you get people to realize that you have feelings to? Serious responses only.