I study english and russian language. I need to be able to speak fluently in both languages for some purpose. but it's so hard to study in the same time. When i speak english, without conscious I use russian vocabulary. So I'm curious how other people who can learn some languages in the same time can handle it.
I studied French and Spanish at university but I honestly think that I could only do it because I had structured lessons. If I had had to do it alone, I doubt I would have succeeded. This doesn't mean that you can't though! Russian borrows a lot of its words from English so take heart in the fact that if you do use a Russian word, maybe the English speaker will understand anyway. Don't give up - it takes practice and patience, but you'll get there :)