I'm a classical musician so most of my music will probably be not super appropriate (i could make a case for mozart's lacrimosa, literally the work he wrote before dying, in a requiem, a mass for the dead. chilling)
non classical music, i would probably recomend "Call it fate, call it karma" by the strokes. really mellow for me.
"Undenied" by Portishead is another one i really feel.
I'm italian and the italian song "Maladie d'amour" really hits me so much, talks about loneliness and being abandoned by your loved one.
"Present tense" and "How to dissapear completely" by radiohead are insanely depressing to me, but any radiohead song that is slow and sad could work, i totally recommend them, trust me you wont be dissapointed. (If youre interested in more radiohead feel free to say so and i will recommend some more :)
All of tv girl could work, if you're interested. "Love machine" really hits me sometimes, but its more of my memories of listening to it years ago...
I'd lastly recommend you to find music you used to listen to, maybe the ones that feel incredibly nostalgic. Those songs hit the hardest.
I hope you stay safe :)
Take care