Lack of Confidence.
Well, I've been self-teaching English for about 10 years now but I still don't feel comfortable speaking with friends or using professionally. I have one American friend who speaks Portuguese really well and every time I'm talking to him I always use Portuguese instead of improve my English skills. He told me my English is good, but I'm not that confident for some reason I can't explain. I've been watching videos and movies only in English for 2 years and even though I can understand everything I'm watching I still don't feel like I could talk freely. Probably because I live in the country side of Brazil and there's not much foreigners to talk to, then I don't practice my skills, or it's just a fear of failure. But no matter which reason it is, I have to talk or I'll never be able to speak as fluently as I want to. The funny part is, I can sing in English, and love rap, sometimes even change the lyrics to fit my spirit or because I think another word would fit better in that sentence, vocabulary is not a huge problem for me (I need to learn more and more everyday, for sure, but I can survive easily in a English speaking Country), the problem is always lack of confidence. Maybe someday I'll get over it and just let myself make some mistakes for the sake of improvement.