Currently, I switched my training from cross training to run.
As Spenser san's suggestion, I am running 3 times a week.
These are my running logs on DailyMile.com:
November 26th, 2016 (6.01 km) My lungs are out of shape.
November 28th, 2016 (8.31 km) After going over two killer uphills, I was running dead.
November 30th, 2016 (4.7 km) Should have run 0.3 km more to make it 5K. Well, next time.
December 2nd, 2016 (5.41 km) I was being chased by the ambulance. Or I was running in front of them.. I dunno
It's still only 4 times now, but hopefully, I can keep going.