You have irritating an irritated knee. Swelling is reflection of knees anger as it is not liking the activities that you are asking it to do. You have weak muscles of leg plus knee osteoarthritis especially of the patellofemoral joint.
Next Steps
do x-ray skyline view of both knees, sit on heights from where you can easily get up, frequent breaks, no exercises
Health Tips
we can do a teleconsultation if you want