Feeling defeated

I recently had an interview that resulted in a job offer. At the time of the interview three different shifts were mentions and I expressed interest in all three. I recieved calls from three different people in communication to the offer and what shifts and also when to come in for my health screening. The same day I had the offer I accepted 2:30 to 10:30pm. However, I had to delay my health screening because I had to wait for my daycare spots to be open. (My fiance just got a new job that he couldnt get time off in the next two weeks.) Do you know how hard it is to find a decent daycare with TWO spots open in two weeks time! I have twins. Well, on the day that I call them with a day that I can come in for my health screening. ( Only 2 days after my job offer.) They tell me they are recinding the offer. I was silent, in shock! All the hours and stress I had endured to plan for this! They said they didn't feel I was committed and were going with a different canidate. I feel heartbroken and let down. I've been a SAHM for almost 2 years with my twins and I'm pregnant with my 3rd. I needed the health insurance and money. I feel like I was doing alot to show my committment! My fiance and I have no family around for short term childcare and I just dont know what to do.