Is it my fault that my parents are on the verge of separation?

People can separate for many different reasons, so it's impossible to give a yes or no answer. Despite this, the separation is between them, and shouldn't bother you in anyway because it is their choice. You may still be upset about it, but if they believe that it is the healthiest choice for not only them but you as well, it might be better for your mind to not question their reasons. This, however, can be very difficult because it may be directly affecting you, so if you do have questions, it may be a good idea to sit down and talk to both of them about how you're feeling and ask as many questions as you want. It's their choice on how they answer.

No. Even if they blame you it is not your fault because a marriage or a couple separation has to do with the two of them. The couple's separation usually has to do with differences in which they cannot resolve. If you should feel that it's your fault in some way then that would be false because it is easy to blame somebody else and if they didn't blame you then you have nothing to worry about. I'm sorry for the separation but sometimes people are better off separated then together and if they do get counseling maybe there is a tiny chance they could stay together but this is between the two of them and has nothing to do with you so please don't worry,!