Do I have runner's knee

Newbie

I have been running for about 10 years. About a month ago I felt a twinge in my knee cap. All my runs from that point on have involved pain on the outside of my knee which then moves into pain behind my knee. I recently changed my stride and have been running on my forefoot and toes.

I ust got a new pair of running shoes and have tried to change back to my old stride. Yesterday I was about 1 mile into the run and my knee felt like it was going to buckle. Is this runner's knee? Or IT Band problems or both? I am terrible at stretching but have been religious about it for the past couple of weeks. I am so sad and depressed, will I ever be able to run again?