During a conversation you just have to accept your mistakes because there's no going back and correcting them (you have to be 100% comfortable with your mistakes because it's crucial for your fluency improvement to speak freely albeit with some imperfections), but when you write, you have the advantage of being able to go back and change things around.

If you want to learn English speaking and writing, then you need to set clear goals. Goals give you something to work towards. Start with small goals, and as you meet these goals, celebrate your achievements. Then, make new goals. For example, one goal may be to have a conversation in English with a stranger. This is a great goal that is something you can work on, and once you do, you will feel proud of yourself and recognize how far you've come in such little time.