aaaaaw hunni i really feel for you *hugs*
my mum used 2 be completly unreasonable, around 2 years ago, jus after she had split up with my dad altho it was her decision, she was like that in the end things got so bad my brother and i had to move out (stayed @ my dads), she was always lying to us and became really ciniving, she'd say i could do something and then change her mind @ the last minute, n i saw no reason 4 it except to hurt me. after around a year she bought a house with her partner and we all moved in 2 it, ever since then, literally she changed over night, we've become so close and looking back i guess she was like that because she was stressed about supporting us and becoming a single parent, i realise now that @ a time when she needed my support the most, although she seemed 2 push me away, i never actually stopped 2 ask her what was going on, i could've helped her so much and i didn't and i regret that know.
Things are better than ever now, were so close as mother and daughter, please don't get me wrong im not trying to rub it in, jus trying to emphasise that there will be a reason why she is acting the way she is, and if she is finding it hard to deal with then she is likely to push you away. u need to sit down and talk 2 her, after all she is your mother, she'll prbably need it more than you ever imagined.
hope that helped, sorry it was a little long winded, i truley hope you work it out x x