Oh Mother...... Geesh!!
Aww geezus girl. I'm sorry. I think your mom is so interested in how well she's doing, and how much younger she feels, that she doesn't realize how she's taking it out on you. She needs to step back and recognize.
Maybe you should make a comment to her. Like, the next time you two go out shopping and she pulls the "This is too small for you" stunt, tell her "Gee thanks for voicing that outloud, Ma". Maybe she'll get the hint.
Mothers....wow. My mother is a beautiful and kind giving woman. As long as you don't tell her she's wrong. Then she gets all pouty and mean and says things like "oh, I am the worst mother in the world, aren't you sorry to have a horrible mother like me." LOL As I got older I started calling her Mary Martyr. We have a very good relationship now, not while I was growing up though, and i am able to tell her to chill out. Sometimes the ones we love the most are the meanest to us, for whatever reason. I guess you can say it's on her and not to worry about it. Just go on like you have been doing and perhaps stop shopping with her. This way you don't have to deal with that particular situation.
If my family member had said something like that about a closet of fat clothes i would have said "why should I take all your fat clothes when you obviously need them?!?!" haha, i'm a ***** sorry.