Is there light at the end of the tunnel?

I try to stay a positive person even through everything that is happening in my life right now. I have to believe that things happen for a reason and even though things aren't going so well at this moment that there is a light at the end of this dark tunnel. It has to get better! If I didn't believe that I'm not sure I would be able to get out of bed every morning.
Today was just a rough day in general. I woke up with a migraine and the kids were misbehaving, screaming, and into EVERYTHING all day long. Tonight as I sit at home I'm feeling overwhelmed.

The light at the end of the tunnel seems like it is disappearing rather than getting brighter.

And the sadness sets in

It has been 3 days since I found out about my husband's secret messages on the internet and this is the first day that I'm actaully sad. It is the first day that I cried. You would think that I would be upset about losing a man that I married almost 6 years ago, but I'm sad that I don't want to work things out. That I would rather walk away from him instead of staying and repairing our marriage. I'm sad that I regret marrying him at 18 years old. I'm sad that I wish the kids weren't part of the picture because things would be so easy. And most important I'm sad that I'm taking our family away from my boys.