Maybe write them a letter and give it to them. Maybe if they see it in writing, it will make them listen and talk to you.
My guess is they aren't telling you too much because they haven't decided themselves yet. But if they know how much it is upsetting you, maybe they will be forthcoming or at least explain why they don't want to share details with you. If they realize how you feel, maybe they can at least sit down and say, "we haven't decided yet."
If they are changing their mind a lot, it is my opinion that that shouldn't be shared on a frequent basis with children. It can put the kids through a lot of stress that shouldn't be part of their lives. (I use the word "kids" loosely, to include offspring of any age, including teens.) Thinking back to my own divorce, when we moved to separate bedrooms, I explained to my kids (one teen, one younger) something like, "your dad and I aren't getting along that well right now, so we're taking a break and sleeping in separate rooms." I couldn't tell them, "we are getting a divorce" because that wasn't decided yet. And I didn't want to not say anything, because then they would be worried what was happening--why aren't mom and dad sleeping in the same room anymore, are they splitting up? They needed to be told
something.
I don't think kids should be part of the day to day discussion about whether to get a divorce. Kids could think it was their fault and if they behaved differently, they could save the marriage. The divorce has nothing to do with the kids' behavior or actions, and that burden should not be offered to them. If Mom and Dad are saying things openly to each other, in front of their kids, like "I just can't take this anymore, I want a divorce," that is very inappropriate.
I feel really sad that you are going through this right now ACQPL. I hope your parents can treat you respectfully and lovingly and not make you part of their issues. I hope you can get them to talk to you. Try the letter.... If you can't get through to them that way, maybe try, "Mom and Dad, I am really stressed out about what is happening with you, and it is not getting better. I know you have your problems, but this is a problem for me too. I think I need to talk to someone about it. Can I see a counselor?" I know that's a speech that is way beyond what you should be expected to have to make. But if your parents are not getting it, maybe that will hit them over the head with it. A counselor could help you with ways to deal with this stress, and might also be able to get help get your parents to handle this better (their interactions with you about their marital problems).
Please check back in and let us know how you are doing.