"Will I ever be fluent if I speak so slowly and carefully?"

Don't worry about fluency. Fluency is easy to achieve by simply talking. If you practice speaking, you will be able to speak faster and faster. In high school, Tom achieved pretty good fluency in a month by talking to his English teacher (a native speaker) about two hours a week. That's only 8 hours of talking.
In our opinion, it is much better to be slow and correct than be fluent and make a lot of mistakes. Why? Because if you are slow and correct, you can easily improve your speed and become fluent and correct. But if you are fluent and make a lot of mistakes, it is not so easy to remove your mistakes and become fluent and correct.