How To Treat Enlarged Adenoid,recurrent Cold And Cough?

Hello Doctor My daughter,Aega, is two and half years old.She is been send to playschool.At home my child is active like any other child.But her class teacher said that at times she seems very tired at school, that she always want to find a comfortable place to lie down and some times she is ok - active and happy to play with her friends.Teacher even asked me about my daughter s sleep pattern - for which i replied - from 9.00 pm to 7.30 am.After that i have changed it to 8.00 pm to 7.30am.At school also they make her sleep for two hours.Even then i am told that my daughter is tired. My daughter has cold always(and associated cough sometimes).Her cold comes and goes.When she has cold, we take her to hospital and her doctor pescribes antibiotics and antihistamines.It will be given for around 1- 2 weeks.Then she will be fine for 4 - 5 days.Again she catches cold...and the cycle continues. Recently her doctor had told us that her chest is clear and it is confined to nose and throat and so it might be because of enlarged adenoid.Due to this she has difficulty while sleeping.She has snoring.She rolls in bed from one place to another searching for comfortable position while sleeping.She mostly breathe through mouth.Doctor told that it should be surgically removed or wait until it shrinks. What should we do - Should we go for surgery or wait? Why is my child not very active at school - is it because of her disturbed sleep or any other systemic problem? Worried mother....please help...