I'm just starting out w1r3, but messed up r1 with trying and failing to run up some of the slopes near my house. I've had a painful knee since then. I' be done two more runs since then, and managed them OK, but my knee is really painful now. It's a bit sore on the run, but afterwards it really gets painful. I walked about 3 miles yesterday. Stupid idea but it just sort of happened.
Is there anything more than rest, ice & painkillers that I can do. I don't want to lose momentum and start again if I don't have to, but I don't want to be even more stupid!!!
Right now rest is the best thing, you don't want to injure yourself further. Don't worry about losing momentum. You sound determined and once that knee is feeling better you'll be right back in the saddle.
Once your knee does feel better, you might want to look into extra stretching and some strength exercises to help build up those muscles.