The symbol of happy/sad drama masks (Thalia and Melpomene) is an ancient reference to this same dynamic.
Was prompted to look up the definition of the word "pathetic," recently, and it means evocativeness of emotion, but typically sympathy or pity instead of laughter. Being comical and pathetic seem like the same thing, we just don't understand the word well because it's an epithet in pop culture that nobody considers the meaning of. When you look at a lot of art or music as pathetic in that they are aimed to stir a kind of nostalgia or sorrow, it's the same underlying art that produces laughter and joy. It's like a spectrum of Handel to Chopin, where one evokes soaring joy and the other a sense of nostalgia and memory.
I'm very funny, but I also make very pathetic art as expressions of the same underlying capacity for pathos. In the essential meaning of the word comedy is a pathetic artform that refines out the neutralizing emotions and produces pure involuntary laughter. Whereas the well of personal experience the performer uses is going to have all the "sadness" (in the form of wistfulness, nostalgia, romance, etc.) as well. Someone who is funny or brilliant or entertaining operates using pathetic (evocative) means. This "sadness" of clowns is only a problem when we judge or criticize it.
Really, if you can just see your comedic sadness as a natural capacity for pathos, (and take the Zen view of not being your feelings) it's another source of creative energy.