I cannot run without calf pain

I am slowly coming to the conclusion that I cannot run without damaging myself. I'm starting to get concerned that not only will I not be able to run the full 10k I have signed up for on the 28th of May without stopping (that's not even an option now), but I might not even be able to make it round the course running/walking on and off.

It's two things - firstly my left calf muscle/shin which I damaged running last year but I ignored it, I've been for physio on that a couple of times in the last month, and whilst it seemed to help the muscle heal quickly, as soon as I run again it tears and I'm back to square one.

And secondly, the fact that I've been doing so much work on that left leg with exercises and stretches means that I am running differently, and that is putting too much strain on my right leg, which isn't used to being forced into unfamiliar positions. The entire leg fatigues after about 7 or 8 minutes of running and feels decidedly odd, it's hard to explain but after a while I can barely even walk on it.

So, I think after this 10k (which I will have to get through by means of half run/half walking, I think), I will have to hang up the running shoes. It's a shame, because I would enjoy it if it didn't hurt. I see other people just popping out for a quick jog and get quite jealous.

I will certainly rest up for a few weeks after the race and carry on the strengthening exercises. Maybe after that I'll go back to square 1 with the training and see how far I can get without pain.