Breakups do suck, especially after as long as 4 years. It sounds like you need to take some time to work on yourself, get to where you’re good on your own. It will take time to heal, but once you do, you’ll be in a better place to look back and reassess. I know we’re often told the story of high school sweethearts that stay together until they die, but that is the exception, not the rule. I know it sucks and hurts right now, but you will heal with time.