You are off to a great start.
You are already doing more exercise than most do.
But pleasantly, as you keep at it, and the better/more fit tennis player you become, you will likely feel the urge to do even more! That can be more hitting/playing time, or even adding in some agility drills and HIIT that you can read more about on the sports fitness adviser site.
You've gotten some good advice above on eliminating the junk food down to keep loosing weight.
In the long term, you will constantly modifying your routine, and paying more attention to the concept of "cycling" regimens to work on strength, quickness and your tennis game, and more attention to your diet to have the strength and stamina to keep on going.
Welcome to the world of the healthy and fit.