Hello !!!!
I can understand that the pain is killing you , but don’t worry , it will get okay.
The symptoms that you tell of can be due following causes :
1. Ligament sprain or tear
2. Degenerative condition of knee
3. Bony avulsion
In all of the above mentioned conditions, through examination is must.
Next Steps
Consultation , examination and investigating is must.
Till then some Hot fomentation , anti- inflammatories and a keto-parch can do the job.