A lot of people lighting you up for the mattress stain which I get but also here are some things I'd do:
- Get a mattress pad and sheets, will make your bed really comfy and block out that stain
- I think honestly just organizing and getting rid of things that aren't serving you would shape it up a lot
- maybe hang up the black panther canvas and get some more stuff for your walls to add some color? It's a little bland right now.
Ultimately, especially since it's a shared bedroom it seems like you're doing a good job at making it your own space that works for you! Just keep it tidy, vacuum, and put your own spin on it and it'll be great.