I’m a non-custodial parent living abroad. As a U.S. citizen I file a tax return in the U.S. in addition to filing in the foreign country. Looking for guidance on whether to use foreign or U.S. tax return for the CSS Profile. Thank you.
If all of your income is reflected on the US tax return, then those would be the numbers you need. Count yourself lucky that you aren’t having to figure out how to convert a foreign return into something that will fit the lines of the Profile or FAFSA. 
I haven’t filed that kind of income tax return since back in the last century, now it is just a foggy memory of nightmarish paperwork. Truly, you have all my sympathy!