Trouble finding myself as a mummy!!?

Hi i am 21 married and have a 4 month old baby girl, i love my daughter but i cant help but miss the life i had before she come along, i know this sounds shallow but i miss being thin and everything sitting perky. I miss the freedom the time i had to myself and the extra money. I feel like i do the same thing day in day out and i am miserable. I have tried talking to my husband but he does not understand. I just feel like i am not enjoying my life but then i feel very guilty for wanting some parts of my old life back as i love my daughter i had no idea i would ever feel this way. Everything about my life and me has changed and i just cant seem to fit into the roll of being a mum. Have any Other readers has this same experience?? Any Advice??