I’m really sorry that you’re feeling so low OP, I know how hard it is to feel self conscious and unhappy with how you look.
if you like the new clothes then keep them and enjoy wearing them, you deserve to wear things that make you feel good and you should make a point of treating yourself every now and then. It’s important that you give yourself the opportunity to pamper yourself a little. It doesn’t have to be ablout spending money, but taking the time to have a long bath, use a facemask, shave your legs, deep condition your hair, do your nails…… whatever makes you feel good.
when it comes to your daughter you will be doing her no favours to let this slide, your husband needs a talking to too. You are trying to raise her to be a good adult, you do that by teaching her right and wrong, and it was wrong to deliberately and callously hurt your feelings. She knew you were upset, she knew what she was saying was rude and cruel and she did it anyway. You need to explain to her in direct and clear word that what she did was cruel, that not only did it hurt you but it also showed a side of her that is unpleasant to be around, that if she speaks to people the way she spoke to you they won’t want to be around her, that she will lose friends and be looked at badly.
if DD spoke to me like that then something she was looking forward to would be stopped, she would for example stay home and tidy her room while her dad watched her, while you and your youngest go and do something fun. I would also expect her to really reflect on what she did and come back to me with a sincere apology explaining why she acted like that and that she understands why it was unacceptable.
your husband needs to know that he must NEVER encourage that kind of behaviour, laughing along with her was hurtful and encouraged her to continue. Unless he wants to end up with an adult daughter that people hate and avoid, he needs to step up. He should also just be supporting you out of love and concern for you.