In order to grow sometimes you have to let go.... Believe it or not letting go is the hardest thing to do. Imagine being with someone for years, then realize you outgrew that person. The person you once saw your whole life with is now someone you don't even want to be next to. But it's hard because that's all you know. Would you stay because it's comfortable? Or leave because you know your worth? Most people would stay because they love the person. I know this may sound kinda harsh, but love isn't good enough. We have to understand that we can love from a distant. You don't have to be with someone because you love them.
You also have to look at things in a positive perspective. Endings can have some good to it. Some people are better alone believe it or not. These are people who like to prove to themselves they can do it. Some people need to see the real them, and sometimes the only way you can see that is being alone. You can block your blessings being with someone who wasn't designed for you. That's why you hear so many stories when people say "my life became better when I left so and so"..