l the time in the world... not

my mother made me and my sister promise that every year, we will go on a family holiday no matter what. We promised, but little did i know that i would be suffering at her expense. My sister has decided that family holidays are a maybe, she recently got a boyfriend you see. she wants to go on holiday with him, and then there is the issue with our dads family holidays. I have recently got a part time job after graduating university. The job crisis made things harder, circumstances made me desperate. My darling mother decided to tell me ONE MONTH before the payment deadline that i need to cough up more money than i earn. she complains that she cant afford it if me and my sister dont pay, how we are adults and should be able to afford this etc. Because of this, i have had to cancel every plan i have until after my birthday (which falls within the month deadline) to try and at least pay off some of it. She makes me feel guilty because "you promised annual family holidays!" or because im an adult so therefore i should be able to afford the trip. It all just irritates me. My mother has offered to pay any money that i cannot, saying that i can pay her back when i can.... but all of this fuss and stress, when she could have told me she was booking it and working out payments when she booked it.. AT THE END OF LAST YEAR. I love her, with all of my heart. And i understand that shes figuring life out as she goes... but so am i.