pressure makes it harder to just be okay with an off day. hope the system gives you a break soon.
studying with friends often turns into hanging out, which is a different thing from having someone quietly working next to you. that presence alone makes it way easier to stay in your chair, it's called body doubling. I built coquiet.app for that, it's my own project, free focus rooms with calm music and other people there. and make the start ridiculously small, just open the page and read one paragraph.
two rough days in a row can make it feel like everything is broken, when really you just need a few easier ones. the headaches and bad sleep on top of it make it so much harder. be kind to yourself while the system spins back up.
SomaFM and Radio Paradise (already mentioned) are great picks, both listener-supported and basically ad-free. If part of it is the being-alone feeling and not only the music, one more option: I made a small site, coquiet.app. It plays calm ambient music with no ads or talking, and shows how many other people are in the same "room" right now. No account, no chat, nothing to manage. Disclosure: it's my project. It won't replace a good radio host, but some people like the quiet company.