Nice game with the Catalan, but bad endgame again

After this game, I need help understanding the true way of knowing the basic knowledge of rook endgames because this game shown my biggest weakness. Please leave comments below about anything in this game. I will get back to all comments after they are posted. 

I love chess very much and I want to learn what were the strengths and weaknesses that I performed in this game. Thanks for your support in reading this message. :)

It may be useful to keep in mind the saying that the way to win a won game is to first eliminate any counterplay by your opponent.

26...f6 you say "I have to move my pawns and trade as much as possible"

But this is not true.  Black can win a dozen different ways because he has an extra piece.  What black should be concerning himself with here specifically is simply eliminating counterplay... i.e. don't give white any reason to hope.

So for example IMO the move 26.Rh8 (taking the only open file) begs to be played.  Then you can take all the time you want.  Just Kd7 (defend the only undefended pawn he can attack).  And from there you can slowly move up your queenside with the support of your king.

So you seemed to be in too much of a hurry.  Instead of trying to win right away, just take your time and find your opponent's threats instead.  Once you neutralize them the only thing left in the position will be your extra material.  Also try to use all your pieces.  You seemed to be focused on your rook and pawns and forget you king (the bishop was well placed though).

@coneheadzombie I used the chess.com's free engine analysis. 

@Cogwheel I have no idea why Re2 was a mistake. The engine wanted the game to end faster by having rooks on the board (very strange). I wanted to exchange all the down to a king and pawn endgame.

@waffllemaster Thank you very much for the tips. I was getting nervous in the endgame and didn't had the confidence to play that endgame correctly. I had to rush a little bit because I was in time pressure. Other than those issues, this game was solid for me and really pinpoint my exact weakness while playing chess.

How cute would 10. ... Nxg4 11. fxg4 Qh4# have been, though? All I could think about while playing through this, hehe. What wafflemaster did is summed up what I wanted to say more concisely than I could have, and then some. The only thing I can add, really, is that a ? in chess notation denotes a bad move. Maybe you were looking for !, which means good move.

10. ... Ng4: is not a knight sacrifice, because it wins two pawns (not bad either after only 10 moves). White should indeed not play fg4:, but for instance 11. h4 preventing the queen move. Black will play 11. Ne5: and has won two pawns.

I was curious why there are so many question marks in the endgame, because it is a clear win and you bring it home convincingly. I have found some other moves, but I still think that you have played that endgame good. Not all question marks are good in my opinion and 54. Rg1 should have two question marks. My analysis (for what it is worth) starts at move 42.