Endgame Improvement

So I've played chess my whole life almost strictly off intuition & some basic opening repertoire. 

Plateauing now around 2k & seems like I will need some formal training. What are the best resources for improving endgame? Books, websites, open to anything. Thanks in advance! 

Congratulations my friend. proud of you!

Books

Play a medium to hard CPU with takebacks. 🙂♟️

Give priority to basic endings that have one pawn on the board whether there's other pieces on the board too - or not.
In other words - skip pawnless endings to start.
They have very low return on investment. 
Including because they don't come up much.
You already know the most important pawnless ending anyway ...
King and rook versus lone King.
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If you're 2000 in strength you probably know that a sixth rank King with pawn - wins against a lone King even without the opposition.
Possibly the most key fact in chess - after what checkmate is.
And understanding it (there's no 9th rank for loneKing to triangulate back to).
If you don't know - don't let anybody sidetrack you by talking about rook pawns.

And when I add - yes a rookpawn plus its King can't win if loneKing gets to the file in front of that pawn - I'm not sidetracking.
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endings with rooks and pawns come up the most ... but they're not that easy.
Endings with bishop versus knight might be second most common.
Common error there: Underestimating the knight.
The ending with bishop and pawn versus bishop moving on the same color diagonals - doesn't come up much but its beautiful and worth knowing about and the pawn can win in many positions even though one might mistakenly think that loneBishop can sac itself for the pawn on either of two diagonals.
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worth some investment. Basic endgame checkmate positions with rook and bishop.
And with rook and knight.
Not 'endgames' - just the basic checkmate positions instead.
I'll make another post to shorten this one.

I do this regularly with positions from books. Highly recommended.

Checkmates were called endgames in nineteenth century chess literature. They are indeed vital.

@Ziryab ... Hi!
There's checkmates that are positions and checkmates that are sequences of moves.
I'm stating that its the checkmates that are final positions (without moves before that speciifed) that are most key to start study with. For multiple reasons.
One of them being - there's not an overwhelming number of such basic positions.

idk if this works so dont blame me if you somehow lose 500 points but i recomend just analzying lost games and just remembering what the losing move is and what the best move there was. I mean chess is just applying tactics in many other scenarios.

I agree that knowledge of basic Tactics is critical. And intermediate.
All the other stuff will mean nothing without it.