You just keep reminding yourself that "it " is only in this moment and that you are not going to concentrate, or put your emotions and energy into something you can not change right now but rather put your thoughts and energy in to things that you can. You can always find things about your self that will help develop your own inner strength and independence.
If my relationship were incredibly painful but impossible to leave, i would focus on a few things. They say not to look for happiness from others, because in the end you are the only one who will stick around (whether you like it or not :P ). I'd accept that whatever happiness i'm looking for in that person probably wont exist and that I need to start looking for happiness in myself and what I accomplish. I'd probably feel depressed about myself and my situation, but i'd think of it like this; If i don't go through this experience, i'll miss out on a valuable learning experience that may equip me with the proper skills to maintain a successful and loving relationship with the person i'm meant to be with in the future. Even if I don't do much, and am mediocre at what i do, the fact that i am doing what i can already makes me better than so many others out there. same goes for physical looks and health, there are so many people who are much worse off but putting in so much more effort, if i am thankful for my "good luck" i shouldn't let it go to waste with less than adequate "upkeep". Just because i don't appeal physically or personality wise to one person doesn't mean that i'm unappealing in general. But i should admit to my faults and slowly work on acknowledging my weaknesses because that in itself is an improvement from the way i was before. <br />
You can't focus completely on your relationship, so distract yourself with other things. Just because you didn't turn out to be the perfect partner after all doesn't mean that there's no point for improvement. improve yourself for the purpose of pleasing yourself. and if that itself is hard enough, just take a twisted approach and hope your soon to be ex-partner realizes afterwards just how much they're missing out on. who doesn't enjoy the idea of moving on while that horrible ex looks on with regret?
First, I wonder know why you can't leave. Second, I want to know if you're SAFE (if not - leave somehow, just do it). Third, I will encourage you to involve yourself in projects that improve your life, and your self respect, and that will ultimately help you find the courage to leave and get on with your life. You might also find yourself tempted into a cyber (or not-cyber) relationship/romance. This might help your heart, but be careful, as it can also crush you worse. WAY worse. I recommend self-focus, get into hobbies or life-affirming work of some sort, don't get involved with anyone else, and leave as soon as you can.
I'm sorry your spouse doesn't deserve you. You deserve better. I wish you and your kids all the best!!
supportive friends...like the ones here on EP!