Translation of affirmativ

Well why are you doing that to yourself? That is very hard. You can easily write in another language, if you prefer, because I speak many languages and I can understand many more. I only have problems with writing.
In order to quickly become successful, one would have to change certain points, at least in my opinion: After 5 months of learning, I have still not found the grammar practice on which I should concentrate.
Have you ever visited the U.S. before and if so, where have you been in the U.S.? I've been travelling in California, it was very amazing. We have traveled by car. Here are my corrections.