Coping with stress???

I'm a single mother of a beautiful 14 mth old little girl and I work full time for a inbound call center. My job drives me to the point were sometime it takes everything in me to not just get up and quit, and then I go home at night to take care of my little one. I love my daughter with every grain of my soul, but sometimes after I put her to bed I just sit on the couch and cry for hours because I am to the point where I am so wore out that I am having troubles coping. Lately I have been getting tension headaches which are so bad I can't move my neck. Once every three four weeks I get a night off because my parents take her for the night, but by the time I am done cleaning my house ( I only use harsh chemical cleaners when she is not home just in case) it is 4-5am and I have to be at my parent's by noonish the next day. I just don't know what to do, I have been diagnosed with depression . There is no one I can really turn to for help without rishing losing her.