Super stressed, poor, and pregnant?

my sis and i are both pregnant.shes 33, married, her own house, full time job.im 24, finishing up my masters nights, interning 40hrs/wk unpaid.my parents invited my bf and i to move in,rent free, in order to save money.my sis threw a fit and harped on my mom every day about making us pay, that its not fair,until my mom caved.so now i have a 2nd job to pay rent (my BF has 2 jobs also)my mom offered to help me w/ childcare and my sis threw a fit, saying its not fair,and now my mom will be caring for both babies while we work.we wanted to set up our nursery typically, but my sis threw a fit,saying its not fair so we now must forgo the hand me down glider and binet we have in order for my sis to have her own crib, dresser, and packnplay in my nursery.ive tried discussing this with my parents, but they say its only fair that we sacrifice for my sis.she&her husband love bars,golf,shopping,travel and give nothing to my parents.i have no money to live on my own:what would u do? im so sad