You're not naive, none of us knew much about divorce until we were forced to learn. It is possible that you could separate now, wait two years and then divorce, if you both consent. If not you have to do it on unreasonable behaviour - and that's where things get tricky: one person has to denigrate the other, in order to divorce.
And that is NEVER going to be conducive to an amicable divorce.
It has been an eye-opener, that's for sure. And it's amazing how your once very predictable husband becomes very unpredictable. If he is shitty in your marriage, then I'm guessing the divorce may go any which way.
Joy5 is so much further down the path than I, but she's right you have to focus on rebuilding your life, and structuring it in the way you want. In order to do that, you need to understand what the process involves because it is quite a bit more complex than ticking a box saying "I don't".
To put it in perspective, you don't have to ask anyone's permission to have children, you have to ask a judge's permission to divorce. It can be done cheaply, but not necessarily fairly. Get legal advice, understand the costs, and the benefits, they will explain how you can value property, get info etc. You do have a claim on the family property overseas I'm afraid, but that gives you a wonderful bargaining tool.
Getting divorced is not about keeping up appearances, it is trying to assure your future can happen. After 30 years of marriage, and one child, one of you is likely to have sacrified a career to bring up your child. So this is about ensuring that both parties leave the marriage on equal terms.
Hence speak to a solicitor.