Without going all Tony Robbins or Oprah on you ass I have to tell you this:
Gratitude, the ability to live outside of oneself (giving, volunteering, ect), defining your purpose in this life, all play so much into our happiness on this Earth.
I really encourage you to buy some books and start to input some new ideas into your head. There are so many great resources out there to take advantage of. Here on this link are just a few very basic (a little dorky/old fashioned but that's ok cause they are classics) books which have helped me.
http://www.amazon.com/Power-Positive-Thinking-Norman-Vincent/dp/0449911470
I DO feel you. I am a 31 year old stay-at-home mom. I haven't worked in almost 6 years. Today I am freaking stranded here with two preschoolers who make me wanna pull my hair out. I want to get a life. I want to impact the world. I need an outlet. I want to feel important. I'd like some attention, validation, excitement. I wanna be madly, deeply in love.
BUT...
This is how I choose to frame the situation. I say to myself, "Wow, Molly, you really are blessed to have such a lovely home to be at all day with your two gorgeous offspring. They adore you and you have your own private fan club even if they are only 3 and 5 years old. You're really impacting the world by rasing these two kiddos. No telling what they will do someday becasue of this great mothering you provide. Your husband must really love you to work his ass off like he does. Wow, you are adored. Hang in there self, all things are but for a season and in no time at all you will be on to the next important phase of life so enjoy this time and know it is all good.
CHEESY? YEAH! Nessecary to my mental health? Oh heck yeah! I have to psych myself out everyday to get by at times! I encourage you to get some positive into your life via Free podcasts, meditation, prayer, reading, volunteering, joining a group of some kind, go to church, whatever.
You just can't dig deep enoug into your self to make good feelings come out. I have tried and quiet frankly, it's like banging your head up against the wall. You have to input them via books and such.
Speaking of kids, gotta go now but just wanted to challenge you to read something good.