'My style is [everything.]'
There is nothing wrong with not being able to answer the question 'what's your style?' If anything, I see this as a positive thing. Not only because the question is unbearably cliché, but because if you can't describe your 'style' then surely you have achieved the unachievable; individuality.
When I wake up in the morning I would love to just throw anything on and look fabulous. However, the reality is that if I have not decided on my outfit before I go to sleep, there is no doubt that I will leave my bedroom covered in clothes as if my wardrobe had been sick, wearing an outfit that will put me in a bad mood for the rest of the day. There is nothing wrong with being prepared. As my secondary school teachers told me multiple time during GCSE's, 'if you fail to prepare, then prepare to fail.' I hate to say it, but they make a very valid point. I doubt that they meant it in reference to clothes, but the important thing is that they taught me a lesson.
What I wear depends on the day, how I feel, how much sleep I got and how much effort I am willing to put into to looking 'chic.' Some days I will have planned to wear a skater skirt with high heeled boots and a chiff shirt because I want to look and feel that bit more special. Other days I will throw on my leggings and a thick knit jumper because I want to be comfortable, but look good too. The official name is the 'grunge' look; however my mother prefers to refer to it as the 'homeless' look.
What I am trying to say (without going too off topic) is that you shouldn't feel like you have to wear a certain type of clothing and have a 'style' (cliché.) If you do then that's great, but there is nothing wrong with going shopping and returning with a random bunch of clothing items which look like they've been taken from 10 different people. Dress how you feel, and how you want. Simple.