Why did you remove a stone with 209 in the game (N15). That looks like a 2-point loss in gote. If you had played the hane at K19 instead (3-point gote play), you would have been five points better off. Also 237 was a pass, it merely threatens to take the ko next (which never happens in the game). Playing K13 looks better.

I have 4 corners, two of which reasonably big, nobody has anything in the middle, sides are shrunk... I was sure, I was about 10-15 points ahead.

After counting, I was shocked to see that lost by 1,5 points.

Since a wrong estimation cannot possibly be so wrong, this is a clear proof that the game of Go itself is wrong!

... Mr. Nash, you have an excellent, if very subtle, sense of humor.

As a non native I wanted to check whether your use of the word "if" is correct here. My Longman dictionary gives the example: "She is a pleasant if noisy child." So that settles the issue.
Next I checked "lemmata". I believed it was plural of the greek word lemma. But that is not in the dictionary. Now I believe it is from the Latin word lemma, lemmatis. But its plural is lemmates. So can you explain yourself, mr lemmata?