How can I prevent my parents marriage from falling apart?
You don’t have the power to keep your parents marriage together nor do you have the power to destroy their marriage. No one has that power but them. It is important for you to know that. What ever the outcome will be you deserve neither credit nor blame. The best thing you can do is to take care of yourself and do all the things you should be doing and none of the things you shouldn’t doing. But then you should behave that way regardless of your parents marriage. I wish for you the best life has to offer and good luck.