감사합니다!! ^^

I think you are right 내 마음이 설레다. 내 마음이 설레요. 가슴이 설레요. If it means that you love someone so whenever you see him you feel fluttery, I think it can be translated 내마음이 설레다. In my case I use both 마음 and 가슴 on this sentence.