I agree with the rest here. I think it has something to do with your pronunciation. When you're writing it, you don't actually have to pronounce anything and everything's correct when you read it. When you're speaking, it's different because you have the pronunciation to be cautious and pressured about. That's fine though, I think that's normal. It's not your native language anyways. For me, it's the total opposite. I find more confidence in speaking the language rather than writing it. Probably because I find it difficult to spell some of the words and when I speak it, I don't have to worry about the spelling, just the pronunciation. But I guess it differs for every person learning a foreign language. Either way, I think what we need is practice.