Have you looked into state programs? I know my state (MS) offers some financial assistance for childcare for low income families which most families in medical school including single parents usually qualify for. Another area you might look is programs like the YMCA, Salvation Army, or Boys and Girls Club. They often have childcare programs at reduced rates. Also if your medical school is apart of a larger university you may qualify for the university's childcare center if they have one. I can;t imagine what a stressful time this may be, but hang in there, do some research, and find out what your options are.