I think if you have the desire to write you should write, but if you start hating it again you should stop. I have a suspicion that you'll have more fun writing novels than short stories, and you're no longer approaching the market as a completely new author; with one and a half short stories published, it occurs to me that you have done your time writing at a length that doesn't suit you. I wouldn't worry about whether the projected length is "fashionable"; with the best will in the world, fashions change faster than you write.