For the Christian, joy is not rooted in some vague, self-generated sense of well being. Joy is rooted in the character of God and an understanding that Jesus has made a provision for us.
More than you can handle
On the surface, it seems correct to say that “God will not give you than you can handle.” Paul does tell us in 1 Corinthians 10:13 that God will not allow us to be tempted beyond our ability to escape the situation. But it is a huge jump to infer from this that God will not allow you to encounter situations that you cannot handle.