i Want to Keep my Dress a Secret

So yesterday I said yes to the dress - totally unplanned as I went by myself just to get some idea about what might suit me as I really didn’t have a clue before involving anyone else. Anyway, to cut a long story short I fell absolutely in love with dress number 3 and have ordered it. I rang my mum when I got home and she got all upset and burst my bubble a bit. I’ve lived my entire life with her making comments on how I look, what I wear etc so I wondered if it would be unreasonable/mean of me to say I’ve decided to keep my dress a surprise? Everything to do with the day seems to currently revolve around what will and won’t upset my mum and I’m at the point where I’ve had enough quite frankly. Everyone says it’s your day, plan and do what you want but how is this possible when you have someone in your ear making you feel horrendous about your choices? What’s meant to be a happy time is quite the opposite at the minute ☹️ x