Midlife crisis

I feel restless and not in control of my life. I want, no I need to do something productive, exciting and challenging in my life. Otherwise I will feel old. I feel so alone, like I am not needed anymore. The kids have their own lives and rightly so, but even they don't need me. Am I feeling sorry for myself? Well maybe. No more of this nonsense. I still have alot of fight left in me yet and I don't give up easily. I know god has a plan and a purpose for my life. I believe that I can do anything I want to do because the Lord is with me. Right now I want to focus on praying for my children. They are the world to me and I know I need to pray for them. If I did not, I would worry about them all the time.