This collection of songs are chosen by you and range from uplifting and upbeat themes through to more dark things (but I guess happiness comes from a range of places, and means different things to different people). A few covers and a couple of instrumentals here, and big range of genres from folk to death metal!
https://music.apple.com/gb/playlist/heavy-metal-therapy-hope-and-happiness/pl.u-RRbV0o7Fy70Vxe
Heavy Metal Therapy 