Obviously I don't know the specifics of the situation and what exactly is making the marriage "unhappy" or how long it's been like this for, but....My advice is to stay. Stick it out. Work on the relationship and try and repair it. Things were great once, right? - So why not now? What changed? What needs to change again in order to make it all good again? The best things usually take effort...If things get REALLY difficult, why not give her a 'clarion call'? This is your last ditch attempt to make her see reason and change (assuming the major issue is her behaviour). When you get to the stage where you really, genuinely, 100% are sure that you're going to leave - do it. Pack your bags and go on a holiday abroad for a week. Tell her that she is being unreasonable and you simply cannot take any more, and that you need a holiday on your own to get over it all. Tell her also that, when you get back, if her attitude/behaviour hasn't completely changed, or if you get one single verbal attack or the like from her... then you'll be off for good. A week of holiday will give you time to get things straight in your own head and partially recover from the stress of it all. Then, when you return, you'll be in a position to stick to your words and act on them as you told her. This kind of wake-up call might just work.Only one other point from me - be honest with yourself: is it 6 of one and half a dozen of the other? Are you being unreasonable? The "you only get one choice at being happy" sounds just a little bit self-centered? Are your expectations realistic?Whatever you decide to do - Good luck and we all hope it works out well.