lonely on holiday

i just am kinda bored. holidays are great but most of my friends don't live near and there isn't much to do. i sometimes wish there was more to do, i want to go to the beach with everyone, train down, but if this rain holds up that's gonna be impossible. i love the sea in the rain and sun but not many other people agree.
it doesn't help that i am feeling so lonely. i am in a housefull of people and children, mum is a childminder, yet i am lonely. sometimes when i have the house to myself it feels more comfortable. i wish that someone i love would hold me. like i could just sit there and feel comfortable and not like any judgements are near or anything.
my mum and me are always together in the house but we are never together. she is so difficult to understand, she never talks about problems and judgment is massive in her life. she had problems and she passed them onto me. i had councelling for it. i don't blame her, it isn't her fault. i sometimes feel as if we don't have a relationship. i don't want to move away or be pushed away and never have a reason to return to see her. i am terrified that we will drift apart so much and never talk and share that the only similarity we have is a name and a house. i don't want that to happen.
the room me and my sister share has this mattress in it that we need to get rid of, she blames me for it being there when it is a joint responsibility. she actually threw it at me when i was in bed because i had taken it out from under my bed in order to deal with it. i tidied up her mess for years, mum used to say to us that both of us would miss out on treats if the room wasn't tidy and hannah would always not tidy it. i would do it. hannah's mess isn't normal mess, i actually have to catapult myself towards my bed at the far side of the room to get over it. i can't get to the window and door without a major effort on my part. i can't sleep in that environment.

am i asking too much by saying can she keep her dirty clothes in a washbin and her stuff in the boxes under her bed.

it is my fault, if i hadn't tidied it and just made her do it and hadn't given up then she would maybe be used to doing it now. mum used to say to me, just tidy it, you are good at it. that way we can avoid arguments.
now for the past 3 years every time i tidy my 12 year old sister's mess up i make a vow to myself that this is the last time. then when it overwhelms me and i become a prisoner in my own room i give in, this cycle tears me up inside and the whole time i am tidying the mess and slowly breaking all my vows to myself i cry the whole time. i am not just breaking a promise, i am breaking a promise to myself, the worst part is that it is probably my fault.
it sounds stupid doesn't it that all this is over a room. it sounds it, but if you ever lived like it you would feel the same. i am reduced to hurting myself in order to shut up my mum and sister screaming at eachother. hannah never says thank you, and she told me the other day when i left my notepad on the floor beside my bed that i was filthy and untidy.
i can feel it inside myself now, i can not go into my own room because i feel ill and uncomfortable. i must sound like such an idiot.