Is it true that if you are not exposing yourself to the target language for 4-6 hours a day then you are not going to be fluent anytime soon?

I have been learning Portuguese for almost a year and I have not exposed myself to the language for more than 3 hours a day. I only watch Portuguese videos, listen to Portuguese music, read Portuguese books, read Portuguese news, and talk to Brazilians.<br><br>When I think about it, even speaking with Brazilians that is a part of the 3 hours per day. I want to become fluent in less than a year.