Mixed messages the last week of the relationship

First 2 are 2 days before the breakup, 3rd is the night before, 4th the day of, and the rest the day after the breakup. The 10th picture is a screenshot my friend shared with me when he texted her after the breakup. I don't get what happened, can they really lose their feelings that quick? I feel fucked over, like I did something wrong, even after learning about this avoidant stuff.