Hello, perpetuallysad. You disclose in your profile the emotional and physical abuse you suffered at the hands of your parents. It seems you have been brainwashed into believing you are a worthless soul deserving of being treated badly. Has this issue been addressed in therapy?
There are many articles on self-esteem. Here is a good one:
http://www.mayoclinic.com/health/sel...9/METHOD=print
Learning to be more assertive seems useful too:
http://www.mayoclinic.com/health/***...2/METHOD=print
How to say no:
http://stress.about.com/od/settingbo.../ht/say_no.htm
You have helped a lot of people here, perpetuallysad. It is long past time you did some serious work to help yourself. Please consider getting a referral to a psychiatrist for an evaluation and appropriate treatment.
Love yourself. Be well.