Dear Sandika
You should tell us the secret of your very fast Sinhala unicode typing! https://edunet.lk/mod/forum/discuss.php?d=563&parent=3138
In the same booklet with the antonyms යුගල පද හා විරුද්ධ පද there are also යුගල පද. Let us try a new format for it. Just type them one below the other in a text file. See the sample yugala-pada.txt.
Again about 20 is enough for a start to do some experimenting.