I am not sure, but I know that 아주 is many or much and 너무 is too, too many, too much. So 너무 is more stronger expression. 전 도와주시면 행복할 거예요!

"아주" and "너무" means very, many, much. They are same on the outside, but "너무" has negative nuance. ex) You are very pretty (너는 '아주' 예뻐) I slept too much so I was late for school (나는 '너무' 자서 학교에 늦었다) But these days, young people prefer "너무" to "아주" in any situation.