OK, i am going to give it you straight here- i would not go to my doctor for Martaila arts training, and I would not go to my MA instructor for medical treatment- I dont care how much they command respect, not how good they are- they are martial artists, NOT MEDICAL PROFESSIONALS
You got your sifu to relocate you patella last time, then you relied on him to rehabilitate it. now it has gone again.
What do you deduce from this? That maybe he is not the man to heal it perchance?
I am not qualified to teach martail arts, but i am a fully qualified sports therapist who was registered on the GP referal scheme in the UK for 9 years, and I can tell you that you need an accurate scan of the damage incurred on THIS occasion, and from there, you need to undergo proper physiotherapy with a qualified medical professional.
There is simply no other valid way forward for you now.
Every time a joint dislocates or sublicates, the ligaments stretch/break and the stability reduces, making re occurence more and more likely. Its a viscious circle if not dealt with properly. At best, specific strengthening of the leg muscles, along with certain drills to strengthen lateral stability are what you need- and you will need to do them for the rest of your life.
At worst, you are looking at surgery to repair ligaments.
Dont leave your future mobility in the hands of a well meaning amateur- this is real life, and the knee is the most complex joint in the entire body (its a modified hinge). Specialists devote their entire careers to the knee- there is that much to know about it. Your Sifu is simply not up to the task.