Regular readers are very familiar with my antipathy towards arranged marriages. I'm sorry to say, but your marriage is an example of why I am so hostile towards the whole concept of arranged marriage. I know that love matches don't always work out either, but if a couple starts by loving each other, at least the foundation starts on the right footing.
I can imagine that your wife is from a fairly modest background, but had dreams of marrying a wealthy man, and living a life of luxury. Perhaps this is the price of agreeing to an arranged marriage, rather than finding someone with whom she could fall in love. It's not unreasonable to imagine that she had a previous relationship, and perhaps he was better off financially than her family. Under such circumstances, I can imagine further that his family would scorn any marriage proposal, because of this class/caste nonsense? I know these are a lot of suppositions, but if it's anything close to the truth, you can understand why she might feel bitter and disappointed with life.
Even if my suppositions are correct, this doesn't help you in your situation, so let's look at your best options.
It sounds like you've tried the sort of things I would have suggested, starting out by talking with her, talking with her family, marriage guidance, and so on. It occurs to me that you are dissatisfied with your sex life, but how about her? Men pay so much attention to their own needs, sometimes they don't even think about the needs of their partner. Girls love sex just as much as guys, and as the old saying goes: good sex won't hold a marriage together, but bad sex would definitely break it apart. Do you even know what she likes in bed? This is an honest question, and not intended to make you out to be the bad guy, but it's worth considering that an awful lot of things can be laid at the door of disappointing sex.
Something else you may need to consider, if you take a confrontational way of dealing with problems, sometimes, all you do is pack her into a corner, and she may be like a cornered wildcat, all flying fur, teeth and claws. It's always better to try stroking a cat than to hurt it. I don't know, maybe you've tried the conciliatory route, but if you haven't, it would be a good idea to give it a chance.
Sometimes, you may have to swallow a bitter pill in order to cure the disease. If all else fails, divorce is what's left. This is where you really need to think about the children, because, while it may hurt to walk away, it may be the best solution for all concerned. Your children, if they're like most kids, probably hate to see mummy and daddy fight or be miserable and unhappy with each other all the time. Sometimes, it's better if the 2 warring parents split up, as it takes the pressure away, resulting in a much happier children. If you do divorce, you have to make sure that you both have fair access to the children. If it goes to this extent, you must sit down with them, and explain that mummy and daddy don't love each other any more, but they still both love the children very much, and they want to stop fighting each other. If the children think that they are a cause for the divorce, it will leave them scarred mentally but if you and your wife explain that you're not getting along but it's nothing to do with them, they are likely to survive and understand. You may find you get on better with your wife if you're divorced, as you can at least be on friendly terms while both of you get on with your lives.
I'm not sure how much any of this has helped you, but I'm trying to look at this with a balanced viewpoint. The thing is, recriminations and accusations don't really solve anything, they just entrench the attitudes of those involved, and make it much more difficult to sort things out. When I say sorting out, that can include reconciliation, or divorce. The one thing you can't do is to let this thing drag on, ad infinitum.
Whatever happens, I wish you luck and best wishes,