I need advice ASAP!!!!?

Im a registered medical assistant and about 6 months ago I started working at a Clinic, it was a rough start lots of drama with the girls, they didn't like my work but we eventually got over it, so recently i went from full time to per diem and their giving me really lame shifts, like the shifts no one else wants to work, or the give me short notices that i will be covering a shift for some one else that does not want to work and we all know how hard is it to find a baby sitter at short notice, and when i want some one to cover my shift no one wants to do it. so now im to the point were i am super stressed all the time and i hate my job, so im thinking of quitting tommorrow, im done and over this whole situation, I dont know what to do HELP!!!!!!!!!!!!!!!!!