By error I said Yes in box 8 on 1040 schedule B part III (confused Foreign Trust with My Foreign Account). Now should I file 3520 (how) or amend already sent 1040?

[user170932]

I transferred my own money from US bank account to myself on my own bank account in a foreign country last year. In tax forms, by mistake I checked box 8 as "yes" on form 1040 schedule B part III, because confused "foreign trust" with "foreign account". Now should I file 3520 or file an amendment to 1040? What to say in 3520 about my mistake?

[user170932]

Still need help.