You could try resting the knee for a few days along with anti-inflammatory medications such as OTC NSAIDS. If the symptoms do not seem to improve over the next few days, it may be worthwhile considering a detailed evaluation by an orthopedician to rule out other injuries such as those to tendons/ ligaments/ internal knee structures and suggestion of an appropriate management plan.
Hope this is helpful.
After the swelling and pain, you need to strengthen the quadricep muscle specifically the vastus medialis to prevent future patellar dislocations. Start with muscle setting exercises.
I don't think you should go for work until you get perfectly well. You can go to personal injury solicitor for advice if your company is forcing you for work. You are injured while work and you have every right to take rest.