Some “tragedy” maybe

My TBR list is full but I am in need for something else, something that does not belong to the genres I usually read.

I hope the 18+ warning is enough for what follows.

So I am searching for a book where the MMC (nothing against women but it's important it's a guy for this one) has got everything we could want in life, like he has a husband (or a wife, no children if possible), a house, a good job, a car, money on the bank account, an even "above average" life. But he feels like he does not belong, searching for a deeper meaning of life (the eternal question why am I here and what's the real meaning of all this).

I am okay for a happy ending if he finds his purpose but I feel like it could be more a sad ending (like ending his own life or something).

Do you know a book like this one or is it too specific ?

Thanks.