i want to leave, but .....

Hi, i'm new here, and so glad i found this site, I have been married 20 years to my husband, our one son we had together is graduating next month, and I have been contemplating divorce now for 2 years, I have never cheated, nor has he that I know of, but what do I know, he is a compulsive liar! He lies about money, just about anything and everything, I can't understand it! I should of said good bye on after the first date, when I asked him about his past marriage, and how many children he had, he told me 2 , well,, after a couple weeks a friend of mine called me up and told me he was lying about his kids, that he has 3, so when i confronted him about it, he told me the reason he said 2 was because he didn't know if his first son was his or not, (which turned out to be bull) to this day nothing had ever come up about it and he looks like he his dad, Then a m onth after we were married , I got a phone call from his x wife, who i was made to believe was this cheating monster, and she called to warn me about my new husband and his lying ways, i asked her what he lied about , and she said MONEY, so, guess what my husband has lied about the past 20 years? Money! I know it is poorly managed, and god forbid me managing it, and when I have managed it, and trust me, I can do math, it never comes out right, we are always below in our account, I don't know what he does with it! he works, he comes home on time, i know that with the kind of work he does(i don't want to give away his job) but he has alot of time he can take off, and he sure and hell doesn't take the time off with me,(use or loose time) he's on a salary, he make over $100,000 a year, I have always worked, in the medical field, and it seems like no matter what we were always broke, late with bills, we have the worse credit, I just can't handle this anymore, I've grown to resent him like you would not believe!!!!! I was in a car accident 3 years ago, and hurt my back, so i haven't worked in 3 years,but I have mentioned divorce twice in the last 2 years and he talks me out of it every time, I am just waitng for my son to graduate, and I pray i can get the courage and strength to do this,(Divorce him) this whole thing, lack of trust, lies, has put me into a clinical depression, and i am just tired, so tired, and all i want is to be happy again,, No stress, Does any of this make sense to any of you?? what i want to know is, wouldn't this drain you? putting up with lies for all these years, is it a legitamate reason to devorce him? i would think so, please tell me what you think, I am just needing some support, I have no others to talk to about this, thanks,