Why do you Think my oponnent quited?

jh t5xcyiuop.\nhjg
vghj,m
adxrc/
cvnm;

I think he just didn't like playing further without that rook he lost, whilst you still have two

#3
15 Re1+ equalizes
Maybe he had to cope with some real life issue

Probably couldn't find Re1+

You were up a Rook and about to play the devastating Qe6! taking the Bishop. Which would have forked the Rook and Horse and the pawn. You Had a dominating lead.

As mentioned, the end position is objectively quite equal after Re1 which is not too hard to find, but look at this critical line

Re1+ Be6

Now white needs to find Bc2!! (Which I also did not see)

After dxe6 the queen drops, and even Bf5 is not enough.

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Now for some advanced mind reading: White did not see this line, but was planning simply to play Nb1 with tempo (if you didn't move the Q or played Qxa2). However your queen retreat even takes this small joy away, so it is the last drop in the bucket for him and he decides to resign.