I haven't personally read this myself, but I know about David Benatar's Better Never to Have Been, from what I know it frames life & existence as a net negative & is very popular amongst Antinatalists.
Then there are the famous pessimistic philosophers, Schopenhauer & Nietzsche. Schopenhauer has an essay on suicide. (But I think he himself thought one morally shouldn't do it?) & Neitzsche, though a forever nihilist, still had great fits of life affirmation. But you'll have to wade more through their bibliographies. To find what you wanna read.
There's Peter Wessel Zapffe (The Last Messiah), Emile Cioran (The Trouble with Being Born, The Temptation to Exist, On The Heights of Despair). Very different styles of writing & approach to life.
Again, search & see what you'd like to read.
I recently came across this personal blog
https://schopenhaueronmars.com/ (covers RTD, efilism etc.) & really appreciated their articulate expression.
I just read Cosmic Pessimism by Eugene Thacker & though it is about the meaningless of it all, it still paradoxically left me feeling all warm and fuzzy inside. Highly recommend.