Bustercrown, to answer your question. Yes, being miserable is a great reason to get divorced. The only question is if there is hope that things will get better. From what I get out of your post, you have tried and it didn’t help. Now what you have to consider is: are your children better off with your spouse, or without your spouse. Divorce greatly affects their present and their future, so that is something that is very important to take into consideration. If you and your children will be better off, then yes, divorce is the answer.
It is important to see what your spouse’s issues are, and according to that, see how likely it is that such a person will change with professional help. If it is unlikely (and there are a great many books that will help you determine that), then you have to decide for yourself if you want to take that road.