OverEmotional..HELP!!

I am 25 years old and having my second baby! I tried for this baby for almost two years and I finally got pregnant. My boyfriend at the time just treated me horribly and I mad the decision to go through this pregnancy, and raise my baby, alone. My family is not making it easy for me. Eventhough I knew that I would get negative reactions to my pregnancy, I was not prepared for the distress that I'm feeling because of it. I constantly have to deal with remarks about my body, my baby and just my decision to have a baby with this man. I have repeatedly asked my sisters to stop but they just don't seem to think what they're saying is hurtful to me. I know that they joke alot and I am normally tough as nails, maybe that's why they won't stop, but my emotions are wreck these days and I feel like I can't handle it anymore. Along with work and financial issues I feel like I'm becoming depressed and I just don't want it to affect my baby. If anyone has any advice, I'm open to try...