have i lost heart?

The whole process of getting upset and discouraged over the responsibility that is assigned to me is starting to come once again. It gets pretty frustrating because there are just some things I cannot come to terms with. On one hand, I recognize the truth that sometimes we simply need to learn to do the things we need to do, not just the things we want to do. But when we lose joy in doing that something, knowing that serving God is suppose to be a joyful thing, where then does the problem lie? Of cos the answer is my self but I need a clearer answer as I do feel that I am losing heart. I guess I need to seek and pray more about it to really come to terms with the issue at hand. Meantime, just gotta be faithful and prayfully the Lord will show me the way to go...