Crying is one way to release emotions. Unfortunately, the other ways aren't that fun either and may involve being curled up in bed remembering the good times or hating your ex. While it hurts (like seriously), if you were truly in love, a break up may actually leave you wondering if you can die from heartbreak. But you have to get it out.
When we bottle hurt, it just haunts us, following us from one relationship to another until there's not just one person we loved to mourn, but many. You won't be your best self, or your best self in your next relationship, if you don't allow yourself to mourn the most recent one. Plus, while you may hate your ex (and you're allowed to), think of breakups like a death of a loved one (wrote the Scorpio). Despite the bad shit, there was good shit, and it deserves to be mourned.