How did I lose this game? I feel that I played excellently.

7. Bc4. No need to defend d4 because of Qxb7. Whenever your counterattack includes a graver threat, continue the offense instead of stepping on the defense.

Then later when necessary, you fail to defend the same pawn. These center pawns are pivotal throughout the game - you have to keep guarding them. Entire grandmaster battles can revolve around the control of a single center pawn. There's a famous one between Kasparov and Karpov.

17. Rab1. Useless move. It's far better to centralize rooks at this stage. You lower-rated guys are stepping on the brakes all the time - you need to learn to go full on into attack mode! Games that peter out into drawish positions like this are often decided by who gets to occupy the seventh rank first.

48. Bxf3. Bc4 is far better because it gains you tempi. You have to calculate your resources with every move, including tempi, especially in the endgame grind!

50. Kb7. What's the point of this move? What is the king's mission there? At least Ka6 has a point. Completely lost.

Now 52. Ka6 - it's too late by now. That's a surefire recipe for ridicule. Because they see the best move, and all you're left to do is catch up with the opponent's mind. Again, at least Kc6 has a point.

@20
"13. Rd1 loses a bishop?"
++ 13 Rd1 Qxc4 14 Ne4 (threatens Nd6+) Qxc2 15 Rd2 traps the queen.

No idea if this is right or not.  In seconds, I just clicked on the middle of the notation and started clicking through moves.  Clicked barely a few....  Opposite colored bishops, you created tension on the King's side with e5 then e4, then you played b6 instead of Kb6...  I literally didn't look at 8 moves here and without seeing the engine's opinion, I say those were no good.  I may be wrong.