2.5 months- it's harder than anything before?

5 years, fearful avoidant ex, blindsided breakup. I do not understand what to do. I get the whole healing is not linear bit, but I am doing the worst I have since the breakup. I feel quite depressed. I miss them constantly, but I don't understand why.

The first 2 months might have been jsut me recovering from the shock? I don't know. Every night I want to call them, text them, tell them we can still fix it somewhat. I dont even want that. Was month 3 the hardest for you? Am I doing something wrong here?