This is a great question, @Noah!
Nowadays when I feel down or stressed-out, I sometimes take solace in the grooving riffs and fuzzy distortion of stoner rock or psychedelic doom. Other times, I immerse myself in the otherworldly sounds of psychedelic space rock, and in doing so, disconnect from the outside world for a while. It is from the latter case that comes to mind perhaps my ultimate comforting band: Ozric Tentacles.
The Ozrics’ sound is unique and recognizable, incorporating elements of psychedelic-, space-, and progressive rock (among other genres), with a noticeable electronic influence; and their songs are nearly always instrumental. In a way, the weirdly ethereal and evocative soundscapes that the Ozrics create allow me to escape from the world for a while, and instead lose myself in their music–something that I think helps me to compose my thoughts and find a positive mindset amidst all the outside stressors.
While no one song by Ozric Tentacles comes to mind as the most comforting–in my opinion, their songs all have a similar, wonderfully psychedelic and entrancing effect that seems to elevate my mood–I do have some favorites, including “The High Pass,” from their 2015 album, Technicians of the Sacred:
https://open.spotify.com/track/7xsuMzFXfGHQwohmjPE9oO?si=6cf51674a9c041cc
With its blissed-out, synth-heavy passages, ambient atmospheres, and soaring electric guitar leads towards the end of the track, I think “The High Pass” is a great example of a song that I find to be quite comforting upon each listen. Also, around the 4-minute mark there is a sample of crows calling; I always enjoy hearing the raucous calls of crows, and think they fit perfectly in this moment of “The High Pass.”
Cheers!