I’m not going to suggest specific clothes but strategies that might help.
pinterest is great for figuring out the look you like - grab a cuppa and spend a good 30mins scrolling and pinning anything you like without overthinking it and then look at the collection you’ve made. Certain trends/colours/styles will jump out.
shopstyle uk is a website where you can search for an item and it will pull up all the stores selling it.
When building a wardrobe buy a whole outfit rather than an item (although an item that completes an outfit is fine), and then look for two or three pieces that can change the outfit. Never buy anything until you’ve figured out how to actually wear it or it will sit in your wardrobe for years giving the illusion you have loads of clothes when you still have nothing to wear.
On that subject, take an inventory of what is missing. And make a list, on your phone, so you always have it when you’re shopping. Very often the things that we need are quite boring and it’s easy to get swept up by a dress or jacket that you don’t need, or blow your budget on something trendy.
Buy the best quality you can afford. In my case that means looking in charity shops because my budget is H&M/primark so I’m not throwing that out flippantly.
I know people can be sneery about it but getting your colours done is worthwhile - and as a bonus it makes shopping much easier. A good style consultant will show you what you can/can’t wear; what to accentuate and what to disguise. It sounds like you haven’t got a sense yet of what works on your body.
It’s already been said but alterations are key . Getting a gem taken up, or a waist tucked, or a sleeve shortened isn’t expensive but it makes a massive difference. When you think about it, it’s unreasonable to expect mass produced clothes to fit everyone.
Now saying that, different shops work off different dimensions and some shops will never work for you. Don’t let that get you down - you just need to find the ones that do. I can wear linea off the hanger but I’m in between sizes in monsoon and Zara’s trousers are awful on me. It’s just information - nothing to get depressed about! Knowing this saves me time and money if I’m shopping online.
Shopping is horrid, tiring, stressful and exhausting work. We’re supposed to love it but if you accept it for the necessary evil it is, then it’s just another chore. Try and get out for a day trip to a decent shopping centre or department store and try everything on. Treat it as a learning experience, gathering data so you don’t get caught into negativity.
Woah! That was long. Well done if you got this far.