plz! need help with 11month baby eating problems!

My 11 month baby girl has become a very difficult eater.. She started solids at 5months and was eating well but for the last two months;from 9months or so she has become very fussy and picky. There are days when she eats very well and the next day she refuses the same food. She holds food in her mouth for VERY long and eventually spits it out. I have experimented with a variety of tastes and textures( multigrain porridge,plain rice porridge, fruit/veggie purees,chicken, just mashed up rice and dal)but her likes and dislikes keep changing. I usually need to flush down the food with water or diluted cow's milk.. but off late she doesn't even swallow that and holds in her mouth or spits out.
Other wise she nurses well (a lot in the night) , she is very active, she is already walking and is very playful. She has a bad temper and expresses herself by crying very loud throwing tantrums and throwing things she dislikes. She dislikes being covered, her head sweats in the night but she catches colds very often. Her stool is usually normal sometimes little watery and greenish. She is very light weight and small built. Please recommend some remedy to help with her eating and appetite. Will really appreciate. Thank you.