A closeted writer struggling with addiction searches for the murderer of his secret lover as he delves deeper into his revenge fantasies.

Protagonist seems to really live in his head. Is this a story of a guy with difficulties separating fantasy from reality? If so, not sure if stakes are high enough for audience interest.. Unless he is attempting to break into reality.. Then perhaps include this challenge in logline.

Thank you! I think that's a great revision!

You have described the protagonist,(Closeted Writer) described the bad guy or obstacle (Murderer), the goal (Finding Murderer) and the sense of irony (Revenge Fantasies)

I question if the revenge fantasies is ironic enough.

Overall, I feel your logline works though, I took the liberty at removing some of the wordiness.

A closeted writer struggles with addiction as he searches for the murderer of his lover while sinking deeper into revenge fantasies.