I have changed my mind about my dress

A year and a bit a go, while visiting my mother in law she asked to go wedding dress shopping. The excitement of the engagement and the fact that I am a people pleaser got to me and I went. And then she wanted to buy me the dress and again… I felt pressure to say yes. This experience has left such an awful taste in my mouth as I wanted my mum and sister with me, and pretty soon I regretted it. She has brought the dress over and I hate it. Strong words but it’s all I can say about it. I told everything to my mum and she has said that she’ll buy me a new dress. My mother in law is lovely, but how do I tell her? I’m so worried she’ll hate me. I’ve attached photos of the dress (1) and my favourite dresses which I tried on Sunday. Help please.