I'm not too sure I'm with you on this one, Saundu. Your post seems a bit selfish. Granted, I don't know you, your wife, or any of the backstory, but I'd say that I'm pretty close to being in your shoes in that:
-married since 1999. Both of us work, have 2 kids, and maintaining our relationship has required a lot of work, tears, blood (well maybe not blood), sacrifice, communication, the willingness to adapt as we change, more tears, etc. We're still married and our relationship is strong. Doesn't mean that it's been easy.....and that I don't work my [Bleeeeep!] off, and so on.....
I have been married since 1999 and my relationship with wife has been ???
Has been what? How has your relationship been in the last 13 years? Great, bad, average, not what you expected?
..it seems like she is such a wimp..no camping, no willingness to go fishing, NO outdoor sex, no help outdoors in the yard, me doing the dishes (90% of the time), most of household chores ie: dusting, vacuming, firewood, firebuilding, woodstove cleaning, all homeowner mishaps/failures (fall upon me)
Was she a "wimp" and did she camp, fish, etc back in 1999?
Has she changed?
Get over the chore thing. You two both work. Add kids to the mix and both of you should be doing an equal amount of chores.
I do the dishes, vacuum, house mishaps, and much much much more. OTOH, I do not do the laundy, cook all meals, shop for food, clean the bathrooms, etc, etc, etc. Both of us work our asses off, complain bitterly about it, but in the end, the daily/weekly/monthly grind happens...and we make it happen.
Welcome to 2012 and the age of working parents with children.
she has gained a LOT of weight. Lovemaking to her seems like a chore, it seems she has to be in a good mood, She sleeps ALOT and watches Oprah a lot, tonight I went and got dinner on Mothers Day (takeout) she ate dinner in her bedroom.
I'm sure you've aged well too, Prince Charming

Hate to break the news to you, but a relationship (including SEX) does involved work. Lots of it. The kinda work that most guys do not like.
You know, the cuddling, hand-holding, hugging, talking, being "romantic" crap that all us guys have to endure to get some!

Some of us have just learned quicker than others that that's how the "game" called "marriage" works.
It's not just about you....which is what your post reeks of. It's about both of you. You seem to be missing the other half of the relationship here.....
Positives....she makes 80 grand, I make 50, she does all of the books , bill paying and shopping, she is pretty, is a good mother, extremely faithful, we have 8 yr old daughter whom is absolutely awesome,
Why is money an issue here? That's never a positive in a relationship...unless your goal was to marry rich....and by those standards, you are coming up short.
I read recently in relationships that one or both need to feel that the other is giving 110%. Personally I dont feel this, and i have never worked so hard in all of my life.
Sure, but I think it's most important that both sides of the relationship feel loved, wanted, etc. Seems that is missing....
Dogfish and Aunty have given good advice. Start with talking. Find out *her* side of the story. If you think it's medical, get help. If not, get some counseling.
Last bit of advice....if you do opt for a divorce, hire a really good attorney, listen to exactly what they tell you to do, and be the one that files *first*.
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