Diet during injury lay off and rehab suggestions for a fast return

I'm beginning my fifth week out of runing because of a torn soleus muscle and tendon, weekly physio is certainly helping and I don't want to return sooner than is safe.
now i'm not runing my diet is to say the least rubbish!! I don't want to put on weight (fat) so I eat VERY little (I'm very slim) in part because I don't really get hungry and because I work long hours and am lazy about cooking for myself.
Any suggestions as to easy, quick and GOOD food that I should eat?
Also has anyone any exersises that I could be doing to speed recovery. The physio has given some and says to ice before doing them and again after. Going up on my toes kills as does dropping my heel down below heel level and going down stairs is painful. He says that the tears are healing well but that I still shouldnt run. Can swim and do some cross training as long as there's no resistance.
Any help suggestions please.