I think being confident when you are learning a new language can be a challenge because most of the time you don't feel confident speaking a foreign language. In my experience, I often felt upset because I didn't see progress in my learning. However, interestingly enough, yesterday my teacher told me that my spoken English has improved. I felt very happy about that, although I had noticed it too. I have been thinking, since I feel more confident, I can handle my language learning better. I don't worry if I make mistakes because that's normal. I also think it's very important be a determined person, because when you have determination you can do anything! Whether you have the best day or the worst, determination always wins.
And if I could add something more, I want to tell that you should also be patient with yourself and your progress. You will not learn in one day, this is a process that will lead to good results one step at a time.