Mostly I just explain backstory or elaborate on how the characters are feeling in that moment but I'm told this is wrong and that I should "show" instead but I hate showing. Is telling ever okay?
Yes. Back-story in narration is telling. Dialogue is telling...unless it's relevant and revealing. Does your dialogue do all the work in your story? As in, is it like the second scene in Macbeth, where The Captain fills us in on the battle scene that Shakespeare didn't have a big enough budget to do onstage? Do a bit of description of how Desmond got the marketplace, passing the ramshackle old post office; how beautiful Molly looks with those hibiscus flowers in her hair, the flowers she plucked from the trees that are only found on the road from her house beside the swamp...
For me, dialogue can show a lot. How a person responds- do they avoid, do they respond emotionally, factually, obliquely, appropriately? How do they use language?Are there terms or sayings they miss use. That's all how they say it, there is also what they say and how Thier response changes. Are they even trustworthy? Since people rarely talk without other activities or actions there is the opportunity to flesh out the surrounding world with short bursts of discription about what they're doing in between spoken sentences. If dialogue is your thing, i reckon you can it work.
show don't tell is the biggest red herring out there - a good book is a balance of showing and telling, a book that was 100% showing would be very tiresome. I think when people say it what they mean is don't write "Dave was angry" show us him being angry, and let the reader draw the conclusion that hes angry from his behaviour and words ' "For fucks sake " Dave shouted "Don't you ever listen to a word I say" He turned and stormed out of the room slamming the door behind him ' However if you want to tell us that Dave hasn't eaten since the shitty meal on the plane , its fine to say "dave hadn't eaten since the shitty meal on the plane" as it would be both tiresome and irrelevant to show him eating on the plane, thinking the meal was shit, then gradually getting hungrier and hungrier (unless of course either meal or his hunger has a larger plot relevance)
Why do you hate showing? What's your interpretation of the meaning of "showing"? Yes, telling is often okay, but redundant telling very seldom is, and explaining backstory or a character's feelings during dialogue is often redundant. And the really important stuff should usually be demonstrated/shown rather than explained/told. I, too, tend to prefer dialogue. I find that if I deliberately force myself to start with non-dialogue, that tends to start the scene out in a way that supports gestures/visuals/actions/all-that-stuff-that-isn't-dialogue. If I just allow myself to start with the conversation and promise that I'll get some non-talking in there somehow, that rarely works for me.
