Keep Practicing more on things(school, sports, games) doesn't mean I'm getting better?

Well, when I keep on practicing things, I feel like I don't get better at doing things. For example, I play badminton for hours and hours, but in the game, i keep on losing and losing and losing games, even though when I play with beginners. Same thing happen when I play video games for hours, I keep on losing and losing and losing. I tried to find a way on what did I do wrong, but I couldn't. It is just me? I think that's only me. You can laugh at me all you want, and hurt me.