Mileage taking a nosedive!!

[jimmyrickson]

Hi everyone, I'm new to the subreddit but I've had my civic hatch since December of 2016. It's a 2017 with almost 60k on it. I've heard about the oil dilution problem but I honestly don't know too much about it. I'm worried that my car may be facing it though. I used to get between 30-32 mpg in her but recently I've been getting as low as 23....very significant change in mpg. Could it be the oil dilution issue or is it my driving or something else? I've recently added fuel injector cleaner and that hasn't made any improvements. What should I do to combat the issue? I've seen where it's a bad idea to take it to a dealership but I'm not comfortable with working on her for I'm just a rookie car enthusiast and am still learning. If anyone has any tips or recommendations I would be forever grateful.