i had this..but this is only what happend to me, so you may be different case. youve taken about a month off which is good.
What you might want to do is start running like 30 minutes on the grass to start off, but once you begin training do not take a break, it will only make it worse. Once running consistently everyday, begin wieght lifting.....NO SQUATS they will only make it hurt the next day even more(try leg extensions, and once doing those for a while try lunges). Bt also when done running ice, ice and ice, this will be your only cure, if you do not ice, it will get worse, even if it dont hurt...ICE. Becuase when the pain comes back, it hard to make it go away. And try not to get hooked on advil or ibuprofene try to get your knee better so you do not have to rely on it.
I had patellar tendonitis ...and now im pain free...PS when i had it bad i found out that running on your forefoot, made it less strainful on you tendon. Tell me if you get better, or your progress, becuase if not getiing better you should proably have more rest, i had a 20 minute pr during a 3.1 mile race at xc, and no im busting about 450's on the mile, best shape of my life