The bright colors and patterns will be such a glorious old lady style though, when you get old!

I live in Florida & underdressed isn't a thing here. I would bet money that all you really need is a tailor, it's not surprising you would feel dumpy if you have to buy clothes based on your bust size and they are too big everywhere else. Especially if you are curvy petite. There are so many gifted seamstresses working out of houses where I live, it's a thriving cottage industry. There is an ancient old black lady who lives behind us that does my kids' clothes when they are going to quinces and bat mitzvahs, proms, all those fancy ass parties you have to look good for, I can't afford actual evening wear and the seamstresses can turn the thrift store dresses into great looking unique stuff for them. Do not learn to sew. Just find someone good at it.