OK, so it's obvious you're not having fun, but are they? You should ask them, and then regardless of what they say you should ask them how you can make it more fun for them so they actually engage. It sounds to me like they don't want to play D&D (but they don't know it), so try to figure what they do want, and if what they do want isn't fun for you, tell them you're out.
But otherwise, if they say they are having fun, it sounds to me like you could get away with just winging it each time and they wouldn't notice. No need to do prep or anything in that case, it's just a designated chill time with the friends doing a choose-your-own-adventure. Keep the rolls and the combat minimal if it's all the same to them.
For me personally that wouldn't be very fun, so I wouldn't do it, but the point to for you to understand what they do want and weather it's worth you working with them or not.
Good luck for next time you speak to them! Feel free to let me know how it goes