LisaP, I understand completely about "dressing your age", and it's a good topic. It's a personal goal of mine to "dress like a grown-up", and I often - and carefully - tackle this topic with clients. It can get very tricky.....
Of course, what we each perceive as dressing "our age" and "like a grownup" is different and a moving target. For example, what I think looks juvenile or junior on a grown up person - others don't, and vice versa. I think the rub comes in when we're told by someone else that we can't wear something because we're too old. I get that rub because I don't want to be told I can't wear XYZ because I'm 50. Especially not by someone much younger than me. The difference is that I DECIDE I am too old to wear XYZ, and it's on my terms. Soooooo, all this to say, if you think looks like hoodies, cropped sweatshirts, graphic tees and the like read too junior for your style - that is GREAT and you are well within your right to believe that. Stick to it.
To answer your question, my own denim shirt is cropped and works well with skirts and wide crops. A regular denim shirt can be worn loosely knotted at the waist, as a shacket over a tank, or just over the skirt as a top if it has rounded hems. Scrunch the sleeves, add some bling, and Bob's your Uncle!
As for the skirt, you are right to return it if it's causing stress because this is suppose to be fun. NEXT ....and good that you learned a few positive things too.