Please Help Me Find A Dress!!!

Hi everyone :0)
I am writing this hoping that someone can help me. I am a single mother of a beautiful 3 year old daughter, and engaged to be married this next spring. I`m not trying to give you a sob story here, i`m just desperate and need some help. I left the father of my daughter after a 2 year abusive relationship, and have started over. I am currently in nursing school, desperately struggling with that, along with raising a daughter alone. I want her to be able to have the future that I never had.
My fiance currently does not live near us, as his job transferred him elsewhere, and he doesn`t have much money either. I have searched for low-priced wedding gowns everywhere, but I can`t seem to find any in the range that I can afford. All I can afford is $100 to $150 tops, and that`s really pushing it. I have been saving for over 6 months now, and have $95 so far. Does anyone know where I can find a beautiful dress for this much money? It`s also hard to find sizes that fit me, as I am 6` tall, and am a size 18/20 in street clothes (would be about a 24 in a wedding gown).
I desperately need your help, could you please let me know where to go or where to look??
Thank you so much, and God Bless,
Jessica