Perhaps it'd be nice if the guy who tells you to be more like M.M. takes a turn as the DM, if he knows how it should be done better than you, a person who's actually got off their arse and tried their best.

A lot of the improv stuff is basically experience - you'll 'flow' more over time; feeling a bit silly or clunky is perfectly normal for a bit, especially if you're with people you've known for a while. It's basically you telling them a story, so you're going to be getting into character multiple times - which can be very daunting in front of your mates. But you'll get used to it, as will they.

You shouldn't be being compared to another DM, and that's not going to help in any way. Sure, you can watch or listen to things and get a lot of tips, but it's a bit like saying to a brand new up-and-coming actor "Hey, tell you what - act this like Tom Cruise could, okay?" and just expecting them to get it.

Running Phandelver and other similar fully laid-out things is good for getting used to the game, and allows for a little improv in places, but really it's about the players. If they're not having fun, you won't.

The not-paying-attention could be a big thing - what are they doing instead? If they're arsing around on their phones, then that's a bit disrespectful to the DM. Some DMs don't allow phones or similar, some do. If you make sure you have a break in a game, then it's a chance for people to catch up on whatever, have a drink, snacks, veg for a moment then get back into it all renewed. It's always possible that maybe one or two don't really want to play, having tried it and thought it would be different to how it is. It's worth finding out - as the golden rule says, no D&D is better than bad D&D.

I'd stick with it though, find out what any issues are (and speak to the guy who asks you to be someone else; that's not helpful at all) and see if you can resolve them. You'll relax into the narration side of things as you get used to it all. Best of luck!