I'm a native English speaker, I'm 21 and I'm going to learn a 4th language (Spanish).

I'm actively learning Japanese, started German on Duolingo and I want to start learning Spanish as well. I've been excited for a while and finally got Rosetta Stone and a nice pocket dictionary.<br><br>It feels like I'm ruining the path I set out for Japanese by doing this though. I want to become fluent and I'm still nowhere near it. I'm still in high school for Japanese. Will learning another language at the same time screw up my pronunciation and fluency in Japanese?<br><br>Also, how do polyglots keep actively learning new languages? How do they juggle learning more than one at a time. I want to learn so many but I don't know how to keep learning new ones actively.