My mom left everything to my daughter in her Will; how do I cope?

My life has been a series of one hardship after another. My mother and I were estranged for the last year of her life, but we had started talking by email and I thought we were back on track. I am an only child. I have one daughter who is 21 (I am 45). My mother died last month and left the million dollar house to my daughter, which hurts so badly, it’s difficult to grieve my mom’s passing. If there had been other siblings that she excluded, it would have been easier! I work so hard and have nothing. My daughter has her whole life to be successful; I’m constantly struggling, and on food stamps. It’s embarrassing, too. It’s not natural to exclude your child as an heir. How do I come to terms with this? I don’t want to hate my daughter for getting the house; it’s not her “fault,” but I feel so worthless.