Why are they GMs?
It was better I guess. In spite of having better position I had no idea how to increase it. I am simply too weak player to win that kind of positions against GMs. I don't want to look for excuses.
Interesting game. If I didn't know the game's details I would be sure you were playing with opposite colours of pieces 
On the other hand you had a chance and you missed it. That's the difference between a good player and the excellent one. That's why they are called not "ordinary" masters but GRAND MASTERS!
Very detailed analysis, good luck in future games, Mateusz!