I'm sorry about the pain you're experiencing. I had similar issues with knee dislocations years ago (I was actually a teenager at the time). It got so bad that I would just take step (not doing anything strenuous or out of the ordinary) and my knee would just completely dislocate. I got to the point where I would just put into place myself. However, I was in horrible pain much of the time and of course my parents brought me to our family Doctor who recommended an Orthopedic specialist.
It was confirmed that I had ligament damage and surgery was necessary and given that it what it years ago the surgery definitely was quite involved and they had to open my whole knee and the recovery time was quite long. However, the good news I didn't experience problems with my knee for years.
Recently, I have been experiencing a lot pain and weakness and my knee slips (though not completely dislocates like yours). But, it constantly pops and grinds and I'm basically limping around.
As far as your issues I would definitely recommend that you see an orthopedic specialist that specializes in knee issues. Also, if they haven't ordered one yet, you really need an MRI to see what's going on. An MRI will give Doctor good idea of what's going on and how to proceed. So, make sure you get an MRI ASAP.
I just wanted you to know I relate to what you're experiencing and totally understand how disruptive this can be to your daily functioning and activities.
I hope you see the specialist soon and all the necessary tests ordered.
You are in my thoughts and I hope you get relief from the pain you're experiencing and answers very soon.
~ Fiona Jo