1. running in pain is not good 2. running in pain is not good 3. running in pain is not good 4. when is your marathon ? 5. what is your longest run to date? 6. what does physio/sports therapist/Dr/bloke on the internet say?
There are many many more marathons, you dont want to prolong your injury any more, concentrate on rehab and strengthening. You will use your arms/shoulder to balance a lot more than you think.