well im 38, married, 1 child, good job and I too have a higher sex drive than my wife....imagine that!.....women have different needs....

may I suggest a good book:

"His Needs, Her Needs"...I think the author is Willard Harley Jr.

anyway it will answer a lot of your questions

You would be wise to see a doctor for your depression...you may need some medication to get you on the right track

As far as thinking about sex all the time....its not something all that out of the ordinary....men are wired for instant gratification....some worse than others

My wifes lack of sexual interest led me to pornography and so on.....it s not a road you want to go down

you really need to talk to your wife about how your feeling....if you cant turn to your life partner and spill your guts so to speak, then your marriage may be rocky as you say

theres no magical cure, but as I found out while struggling with sex addiction ( still am)....you can learn ways to cope

hang in there...your not alone