Becoming a SoleMate

So, I signed up to be a SoleMate for Girls on the Run.  I'm helping the organization raise money to better be able to serve young women as they work on their fitness and life skills. 

I'm terrified. 

I had to set a goal race to train for, and I picked a race I've done before.  My normal self would be fine with this race, there wouldn't be any issue.  But I'm not normal right now, right now I'm sick.  I have a mass in my pelvis and I am waiting to get surgery.  I hope, once the surgery is done, the pain I am in constantly will be gone and I can train again.  But, what if it isn't?  What if something goes wrong?  What if I'm really sick.  All of that makes me worry.  I hope I'll actually be able to fulfill my goal by finishing the race, but I don't know if I'll be able to.