One of my favorite quotes/maxims is "thank the heavens we don't say everything we think." Imagine if you told your coworkers/spouse/bookie/llama wrangler what you really thought of them? Oh, mercy! I know I can think some pretty dark thoughts when someone cuts me in line or tells me my "slacks are too tight again."
But here's a curveball! If you're in tune with those things that you're holding back -- those times when you don't say everything you think -- it can help develop good comic characters.
You: What the heck are you talking about?
Me: Read the rest of the post.
You: OK. But your slacks are too tight again.
Me: I am as God made me!
Experts agree, writing a comic is not easy: no actors to give emphasis to your words, no laugh track, no musical score and you get maybe 100 words to get your point across ... maybe.
Former UU president and editor Lee Salem would famously (and illegibly) scrawl on comic submissions from even professional comedy writers, "not as easy as it looks."
But back to your unedited "dark side," Louis CK recently revealed that in his delicious "everything's amazing and nobody's happy" piece there was not actually a guy sitting next to him on the plane who said, "this is BS." He said those were the dark thoughts HE was having and he invented the guy next to him for the bit. He also said this was the case for most of his comedy. Louis CK is clearly in tune with the jerk inside him.
Isn't that true in comics too? Look at these comics: Peanuts, Pearls Before Swine, Get Fuzzy, Dilbert. All of them quite successful and all have a character or two who could be charitably characterized as a jerk who says whatever comes to mind: Lucy, Rat, Bucky, Pointy-Haired Boss.
Are these characters just the darker sides of their creators? I can't find the source but I swore I read where Charles Schulz said that each one of his characters was an aspect of his own personality. Stephan Pastis said that very thing in this interview.
Dark/mean characters provide conflict and when you have conflict you can have fertile ground for humor. You can always dial it back if you get too cruel or offensive ... but there is value in that journey ... what will you find? Who will you see? Uncle Al? What are you doing in here?
So, yes, by looking deep inside and listening to your small, charcoal heart, you could find some amazing material.