The solution is pretty simple, even if it requires a little bit of self-discipline and steadiness: buy a method and learn a lesson everyday (everyday!) during approximatively 3 months. 20 minutes for each lesson seems enough to master pretty well the chosen language. Anyway, your brain can't memorize things well if you work too much. So learn little by little, at your own pace, but EVERYDAY !
Reading newspapers, watching news and chatting with native speakers will also help you a great deal.
One more little tip: if you want to watch a film, watch it in your native language but with the subtitles of the language you are learning. This way, you will memorize a lot of grammatical structures without efforts.
It really works.