Discouraged?

I love the way God works. Yesterday at church Pastor Dan did a topical study. It was on 1st Kings, about Elisha and how he had been very discouraged by being down by the river and being fed by ravens (just a very small part of his life) and through out his life there were many times when he was discouraged by life and people, like Jezabel, who persecuted him. One thing that was pointed out was that God was working in Elisha's life during those discouraging times, growing Elish'as faith and glorifying Himself through Elisha's story.
I woke up this morning with a stiff knee..... I haven't run in 3 days because of a crazy schedule so it wasn't from exercising too much. As the day has gone on my knee has gotten much worse while sitting and walking around at work. I was really discouraged since today was supposed to be my 6 mile day. We have a therapy laser at work so I used that which helped a little but after a little while it felt warm and was getting swollen. So that means no running. I'm not sure how long i will be out but its very frustrating! But I do know that my God is in control and He knows why. Maybe I need to just sit and be still and know that HE IS GOD and that through this He is growing my faith in Him and glorifying Himself! Pray for me please!!!