How did you deal with your breakups?

It’s been a week since I got dumped. I’m going about my daily life as usual, but inside I feel numb. This was the only person I truly felt a connection with, and she blindsided me by blocking me everywhere. She only bothered to give an explanation after I messaged her on Google Pay, of all places 🥲. Why do people do this? Get you attached and then just leave without a care in the world?