Maybe you should try do a bit more. My routine that prevents me from having to go outside is:
-Spine stretching. Stand up straight and clasp your hands behind your head. Bend down quickly and touch your elbows to your knees. Rise, repeat 12 times.
-Deep Knee Bends. Stand shoulder width apart hands on waist. Squat all the way down. Rise, repeat until failure.
-Calf Raises. Stand with feet a little less than shoulder width apart. Rise up on your toes and lower yourself down. Repeat until failure.
-Pushups. You should know this, just make sure you are doing them correctly.
-Dips. Sit on the ground. Elevate your feet by placing them on a chair or bed. Lift and lower yourself with your arms until failure.
-Leg raises. Sit on the floor with your hands behind you, propping you up and your legs straight out and close together. Quickly lift your legs up until your body forms a “v” shape. Lower, repeat until failure.
-Bicycle crunches. Lie flat on the floor with your lower back pressed to the ground. Put your hands beside your head. Bring knees up to about a 45-degree angle and slowly go through a bicycle pedal motion. Touch your left elbow to your right knee, then your right elbow to your left knee.
Also I am up to 8.2 on the beep test, just gotta keep pushing. I went from 3.2 when I started 3 months ago, so there are results if you just work hard.