recoveriing from training break / runner's knee?

I'm a first year runner/triathlete.  I need to find out how to bring my running back after taking a month+ off.  I tried to come back too fast and have hurt my knee.  The pain was only 3 out of 10 but runner friends said better sooner to the dr. than later, rather than HTFU.

My sports dr. says runner's knee and maybe an initial arthritis spur on the knee cap.  He's recommending physical therapy and strength training, arch supports, antiinflammatories, and no impact for an unspecified time (see the PT, maybe 6-8 weeks).  He said I can run my last tri of the season next week, but expect it to hurt and to consider switching to elliptical long term.

Bleah.  hate ellipticals...and therapy...

I've been running on asphalt, 1/2 on each side of the road so the camber at the edge of the road doesn't screw me up. 

Looking at my training logs I can see what happened.  I trained consistently Jan-May starting from zip and built up to comfortable 90minute/7.8miles per week.  But in June and start of July, I dropped training hugely.  Week by week, I ran only 35'/3mi, 0/0mi, 28'/2.6mi, 35'/3mi, 0/0mi.  Then in late July I jumped back in.  I jumped ahead a few weeks in the training plan I'm using and did 61'/5miles, 156'/13.5mi, and 67'/7mi.  My knee started aching after the first run and I just kept going.  I hurt a little more/longer with each run and then it killed me during and post race this week.  Still the pain was only a 4-5 out of 10 max...   Cycling and swimming cause no pain.

So now I've got to recover from the damage (runner's knee) and especially learn how to ramp up safely after a break in training.

I know how to adjust my swimming and cycling.  Running is the main issue.

Knee pain:  Is this really a extensive physical therapy/no impact type of problem or is this just a conservative dr?

Arthritis in knee - can running accelerate arthritis damage?  That seems to be what the dr. was implying..

Coming back from a gap in training:  How far back do I dial the clock?  If I move off the roads and onto an elliptical, can I be more agressive than I would with a treadmill or asphalt?  How does the 10% rule apply when you take a month or two off?  Is it realistic to train all or mostly on elliptical and save running for races?  If you have a specific BT training plan for running to suggest, that would be MOST appreciated.

Cheryl