Hello guys im searching somes ost (peaceful or sad ost), i really like instrumental or piano but whatever its ok. i hope u guys can help me and thank u!

and sorry for my bad english!

i would definitely check out the Monogatari series OSTs. theyre really calm, but complex. often repetitive, but in an oddly soothing way. there are lots of playlists on YouTube, but you can probably find them to download around somewhere.
let me know how you like them if you decide to check it out!