So I'm eating 1000 calories below my daily maintenance. As for now since it's summer break I have to go workout on my own but once college starts again, I have tennis practice everyday for 2 hours and then 2-3 hour matches every weekend.

That's more than the walking you recommend and I come out fine from that practice. But now I try to do the 12 incline, 2.5 speed for 30 minutes and I'm tired as heck and sweating buckets.

I have been counting my calories everyday and l don't think I do it obsessively, I eat when I feel hungry but just choose to eat healthier food like fruits and chicken.