No, there isn't any scientfic evidence to suggest that masturbation, however frequent, can cause impotence. It is generally considered a safe and harmless practice, and it's recommended to do it in moderation. However, your habit is certainly excessive, and there is a potential for you to be so habituated with the act (so used to self-stimulation) that actual sex with your partner might be difficult. Again, there's no certainty that this will happen - but we'd urge you to avoid indulging in it so frequently and occupying yourself with more meaningful pursuits.