I’m not great at role playing the characters,

Then don't. I suck at this too, and I tend to narrate my NPCs like a novel written in 3rd person.

I suck at being descriptive

This is a learned skill. You don't have to be too descriptive, just enough to invoke certain imagery in your player's heads. How much you have to do that is highly dependent on your players and how you're running the game (as well as the medium).

and I have a hard time gauging encounters so often they are either wayyyyy too hard, or laughably easy. I find myself lying about what I roll to either keep the party from being one shot, or to keep my bad guys in the fight so combat isn’t over in one turn.

Honestly, you should have gone with a system that had a robust encounter builder, or a system where encounter balance doesn't matter. Building your own system when you've never DM'd really wasn't a great idea.

Sometimes I’ll lie to keep them on “track” and not run aimlessly to waste a session because getting our group together isn’t easy.

IMHO it's Ok to give your players a little shove in certain directions when you've got a more linear adventure designed. Not every game has to be sandbox.