I want to be happy in life again

I want to know how to be happy I can. It seems like I cannot find passion in anything. I love my children and I want to do what makes them happy, however I know I'm not being the best mother I can. I know that if Chip was still in my life things would be different. We would do things together as a family and I would be obligated to do things as a family however the obligation would fulfill me. As it is now, I don't feel any happiness in myself and that reflects on how I treat my kids and how I am as a mother. How did I lose my passion for life, how did I lose my zeal, and how did I lose my desire to always be better? How can one make themselves a better person when in fact they have no drive to do that beyond the desire to be that? I have the fear that my kids are going to wake up one day when they're adults and say, you know my mother wasn't really that good. That is the most horrible things I can ever imagine leaving my children with. They deserve so much more. But I know that if I am to be a better mother that I need to be happy, and I know that is a certanity.  So how can I be happy so that I can be a better mot