Im 20 hours in and know next to nothing about the MQ except I was shot.

I didnt even explore goodsprings apart from the trader. I simply headed east once I finished creating my character and havent looked back.

The main quest exists to lead you to various setlements where to complete side quests, and explore all the interesting stuff on the way. It's the "trunk", while everything interesting is in the "branches"

That's how i play Bethesda's games, and seem to work pretty nicely for New Vegas too.

I didn't go find Benny until I was about 60 hours into the game. Now I'm 80 hours in and I still have a ton of stuff left to do and see. I'm playing on Hard w/ hardcoe Mode on. I'm not sure if that's slowing things down or not. I've mostly just been doing side-quests and neglecting everything else. There's no shortage of stuff to do in this game.

I've reached a point where I'm can't really continue on in the main quest because I don't know who I want to side with. I can tell I'm reaching the endgame where I'll have to commit, and it's fraying my nerves a bit.

I'm 150 hrs in on my first playthrough and just starting to get into some of the main quest events. Lots of fun, but still tons more locations to explore in the wasteland and more interesting characters and side quests.

Playing hardcoe + very hard

Following mods installed, all three of which I highly recommend:
Populated Wasteland
Expensive Wasteland
Harder hardcoe Rates

100ish hours and know I need to find Benny, that's it.