You placed this in the wrong section. You should switch what you entered for "for learning" and "base language" so that this question gets filtered into the appropriate forum.

You have to be consistent with your study. If you are forgetting the issue is you are not focused when you study or you let too much time pass between study sessions. Challenge yourself to study for an hour and post a few sentences in the notebook section everyday for 30 days. 매일 열심히 공부해요!

Aside from going to Korea or taking a class, you could try the Memrise app and I'm pretty sure there are a few online courses sponsored by the Korean government.