I was too once learnig multiple languages at a time. However, I've discovered that by distributing your attention to 5 different things, each one receives only 20% of your best. It's not practical from my point of view, especially if you plan to speak those languages. Yes, you can learn 10 languages at one time, but only to get some certifications, but on the long run, you will forget almost everything, especially if you don't use them.