Unfortunately I wasn't able to breastfeed, as I didn't get any milk, so this isn't really an issue. (weirdly, my friend had a baby four weeks later, also had a 3rd degree tear, and she also hasn't got any milk - not sure if it's coincidence or not!)
Thanks for the advice - I may just try run walking this weekend, when hubby is around, as the doctor ferreting around has made it a bit sore! I can sit fine and walking around doesn't give me any problems, so I'll start very carefully and see how I go.