I haven't watched that movie, but spent many years in a loveless and apathetic marriage. Marrying very young can create two adults who eventually have very different views on where their life should be. If, and really if, you have made every effort through this site or any resources that you can find to try to make your marriage work then there are times when one must call it quits, as painful as that can be.
What I would not advise is getting involved with anyone else until the whole process is complete. I made that mistake, and trust me, it makes life so much more complex and difficult than it should be.
In an ideal world we would find our life partner and stick with them for just that, but life is not always ideal. I know this is a marriage building site, but just as all buildings can have architects, structural engineers, builders and joiners, if at the very start, the foundations are not correct, it becomes more and more difficult to paint over the cracks. The very best decorator in the world can only do so much until the building has to be condemned and one has to start again doing it all properly, whether with your life partner, or a new one.
Not perfect by any means, but, at times, reality.
Good luck. Work hard on what you have, but if it fails, then make sure you work harder and what you have in the future.