Calf injury – half marathon vent

So frustrating. I have a half marathon this weekend but have lost the last 3 weeks of training due to a calf injury (possible minor strain) and a chest cold. Chest cold is finally clear and after 2 weeks of absolutely no running, I can run sloooooowly with only 1-2 pain in my calf occasionally. Still deciding whether to try and walk-run it or DNS. I hate wasting money and it feels like that's happening either way. Ughhhhhhhh.