So many lovely posts here!
There are two things going on here, the way you look and the way you feel about how you look. It's fine to do things that make you look better, and even better to do things that make you feel better. Nice shoes, scented handcream, dangly earrings etc, all make me feel good.
Choose things you love and make you feel happy. Care less about what other people have said, and more about how you feel.
Think of Rowan Atkinson. As Mr Bean, or in Blackadder, he is a very strange, even ugly, looking man. As himself, you just don't notice. You think about how interesting he is, what a nice smile, crinkly eyes...
I don't know your shape, but Asda is best for me for bras. Pretty, inexpensive, and a great range of sizes.
For makeup, Avon is inexpensive while on offer, and has a great reputation. Is there a well groomed friend you could ask to help you experiment?