you are entitled to lone parent allowance, its around 245 a week for two children.
because you are working you might get a reduced rate , but the first 146 of your income is disregarded, so if you earn say, 200 a week, 200-146= 54. 54 euro is your assessable means.
so divide this by 2 ,
so 54%2=27. so your amount of lone parent paid would be 245-27=218
you would get 218 euro per week on one parent family payment.
you will also qualify for fis, this is assessed by your income.
for instance if you earn 200 a week + 218 from one parent family payment= 418 euro.
fis is 60% of the difference between your income and the limit for your two children which is 550 for two children.
therefore, 550-418=132
60% of 132 is 79.20
fis payment is 79.20
you will have a weekly income of 418+79.20=497.20
hope this was clear!
you will also need to seek maintenance from your ex, and this will be assessed for o.p.f. payment.