it is normal for someone to need space to be on their own once in a while but make it a point to talk it out with your husband first. Let him know what you want and he will know how to handle it, but do not rush into making a decision you may end up regretting later.
According to the Bible, yes it is. You must have a real pushing reason for divorce in the bible such as adultery or abuse. If you wanna leave to be on your own, that's another story. Either way, you gotta tell him something!!
Not saying I can't understand an itch to want to go it alone, but he's built his future on a promise you made. You can't disassemble his future for "no good reason".
My advice if you're unhappy is to find ways of reenergizing yourself by learning and exploring new things. You'll not only become a better person individually, but will have something new and different to bring to your marriage.
A word of caution: you are in a precarious place right now and will be open to temptation. Stay AWAY from other men. If you end up still wanting to divorce your husband, you'll want to be able to make a clean break, without the hurt and torment that infidelity can bring to all parties involved.
If you have children and he is a good father and husband, you are infringing on your children rights. If you don't have children, then just tell him the truth: that you don't care for him. He will utter the standard question: "is there someone else?" Be prepared to answer truthfully.
i dont really feel that it is fair on your husbands behalf that you ask complete strangers for advice on leaving him. i will however say this, if he has done anything to hurt you, then it should not cross your mind twice to leave him.