Question on hardwork in tennis?

Some players are just difficult to play/rally against because of their topspin and the depth of their balls. Hitting against the wall is great practice when that's all you have. It'll help you develop better consistency, but against players with lots of topspin, it'll just take time, experience, and practice against those types of players. Don't lose heart. Keep up the hard work and good things will happen. And I highly recommend reading the book "Winning Ugly" by Brad Gilbert. It will help your mental game, which is also a big component in the game of tennis. Good luck with your tennis game!