0h N0! Why am i always losing like this?

Looked like two bots playing each other lol

I note this game is from round seven. Does this mean a blitz or rapid chess tourney? If so, this could be the issue. My USCF was a high of 1790, and I average 1700+ in three-day chess. However, in blitz and rapid chess on Chess.com, I am around 200-300 points lower. Ironically, I average 1770 (high 1900+) in Lichess Blitz chess.
One observation, on move 29...Rc7 should have been 29...Kd6. This move allows strong king play in the endgame and rook protecting pawns on the seventh rank. More importantly, by keeping the rook on the b-file, you are attacking the advanced b-pawn. This endgame strategy is assertive in that it prevents and or hinders the pawn from moving unassisted.

this wasnt rapidblitz

this was a classical game, and ...Kd6 would have only led to a draw at best  vs my much lower rated opponent

Was castling a blunder?

Well played game.  Comments in the notes.

If you have to ask...  Sure and it came to haunt you 25 moves later...  All that aside, the crux in the game came after you maneuvered your king to the square allowing the endgame killer combo on your a7 pawn...  You wandered into defeat...  Apparently assuming your foe was wandering around as well, instead he was watchful for strays and caught one... That's why.

Well played by me or my opponent?

i was black

Me and Devalapalli agreed that the king was best placed on e7. Do you agree?

Unless you are blind or just watching your bot play, how could the you agree with your foe here?  The king on e7 is why his rook sac ( 30. R x a7 ) left you in a hopeless position; defending against two connected passed  pawns.  Maybe you should hire a chess tutor.

Thoughtdancerchoice ke7 is much better that castling earlier on.  Later on, it became bad because black castled and wasted several moves to bring  his king into e7 . King of Checkmates, I think b4 check was unnecessary and bad. Simply taking on e4 with knight would threaten to remove annoying  knight  on b5 by Nd6 , and if bf4 then bd7 followed by g5  .  

I think you mean 26. Rc7, rather than 26. Nd5.

Clearly white was better.

I suppose "when" , meaning on what move, cannot be overly underscored.  I.E., if talking about 11. ... Ke8-e7 instead of 10. ... 0-0 they say it so...  Other wise the only reference in the game to ke7 is the suicidal king trek of yours.  Castling or K e7 on move 10, dunno, maybe that done it, but really, there was a lot of 'game' in between your blunder.  You asked why you keep losing like this, you aren't focused, you haven't identified your losing 'moment' as it.

Identify what squares in your position are the ones your opponent's pieces are aiming at, and remember you have an equal number of those pieces to cover them.  For example, 13 ... e5 or 13 ... Ba5 cover the c7 square.