I did, and as other pp, I didn't realise how bad my marriage was until it was over. We didn't shout, we didn't disrespect each other, but we didn't care about each other either, I was relieved when he was away, but most importantly, I was living my life one day at a time, I felt I was dying inside.
The most difficult thing is that, even if you actively want to leave, you cannot gather any support to do it, because everybody thinks you are not doing that bad, that he is lovely, and he loves his offspring dearly, but people outside the marriage don't realise that you don't talk to each other anymore, that he puts himself before the child all the fecking time, and that it is years since you are staying late for long hours in mumsnet to ensure he is asleep when you go to bed. I confess that even wearing the wedding ring bothered me, so I put it away and just used another ring. He didn't even notice.
I think that my wake up call came one day, when I was complaining about ex (yet again) to my best friend. So she said, "good grief, where is your ring?" And then, "Memy, if someone comes and tells you that he is having an affair, how would you feel??? " the first thought that came to my mind was "Great, at least he will leave me alone for a while!" . I knew there and then that my marriage was over.
I think that a huge amount of women stay in unhappy marriages because they are afraid of raising their children in poverty. So the first step is to deal with that fear by becoming more financially independant.
Things won't be easy but it is worth it. you will be happier and will manage well. The only thing that I can't tell you is that it is far more difficult to take the decision to leave than dealing with the consequences of it.