Separation Anxiety and Starting Daycare

So for 20 months I have been a stay at home mom. Everything has been pretty hectic since I'm really the only one who sees her 5 days a week (fiance works crappy hours where he leaves before she wakes up and gets home when she's asleep). I'm also a full time college student online and taking advanced courses. So we decided it is best for my daughter to get some socialization with other kids and for this mama to get some time to focus on her academics (I need to maintain my 4.0 GPA for my college major program). It will be 3 days a week for about 6 hours each. But lately I have noticed my daughter is getting extreme separation anxiety when she isn't around me. She can't play alone, she won't go to sleep and screams for mommy, if I leave the room for anything she melts down. I am extremely nervous about her starting daycare and behaving this way. Any advice? is there anything I can do to help ease her fears of my being gone?