not a good advisor yet at this point in time, but you did support him financially for his graduate work. For that alone, I think you do deserve a co-authorship.So authorship here shouldn't be the issue.

It is my opinion that you really need to learn to be better at your job.With such a motivated and smart student, it is a pity that you couldn't manage to contribute to his growth and make him contribute to your research program.You are still young and I am sure you will improve with time.