Hoo, boy.. I got a few. To keep this short, I'll just have my favorite lyrics speak for themselves.
"Alone in December" by Underoath. "I'd run to you, but pain awaits. I'm coming home, but I'll be late. No deeper than imagination can be. Sight with nothing to see. What's faith if I can't believe? It's everything. A cure, but I make it a disease. God, take me because I hate me."
"Pretty When You Cry" by Lana Del Rey. "Don't say you need me when you leave and you leave again. I'm stronger than all my men, except for you."
"Let You Down" by NF. "Feels like we're on the edge right now. I wish that I could say I'm proud. I'm sorry that I let you down. Let you down. All these voices in my head get loud. I wish that could shut them out. I'm sorry that I let you down. Let you down."
"Deeper Than Blood" by Phora. "His momma's boyfriend drinks until his demons come out. The liquor takes control of his soul. He don't speak with his mouth, he speaks with his fist, disagree, get beat 'til you're pissed. The type of pain that'll make you put a knife deep in your wrist." I can't directly relate to the song as it's very personal and super anecdotal, but the tone of the song gets me. The chords used in the synths and the pained vocals are that sad stuff I can latch myself on to though.
"Augenbinde x Grau" by Kayou. is a remix of two songs from the Tokyo Ghoul OST in one. It's an instrumental, but damn, if it doesn't get me in my feels. There's something about it that sounds so sad and I tend to listen to it when I wanna write sad scenes.
"Suicide" by Hebona. It's honestly suicidal thoughts put into a song form. Similar to the last one, I use it for very emotionally heavy writing. It taps into my depressive nature so, I tend to stay away from it outside of writing lol.