Every person is different. There is no way to answer the question in a way that will provide consistent results from one individual to the next. The thing about being a zoo is that even though we may have a network of support on forums such as this, at the end of the day, it is still a journey that we must pursue on our own. There does seem to be a few common denominators: the secretive phase, the guilt phase, the slow acceptance phase, the isolation phase, and the "I don't give a F@#% anymore" phase. If you decide that this is not right for you then you must find a way out that works for you. If you choose to accept it, which will be easier, then we are here for you. Most of us who are vocal on this forum have accepted it.
Yes, it is possible to change but it is a very hard path. Some have succeeded, some blew their brains out, and some thought they had changed only to find out years later that they had not and ended up getting divorced.