Lovebombed then brutally discarded, feeling like sh*t since then

Hi, f31, Italian woman working in Poland. I met a Polish guy, my coworker, in February. Intense chemistry from the beginning, he insisted on dating me despite the fact we were working together. We spent 2 passionate months. Expensive gifts, putting me on a pedestal, telling me I was the woman he wanted to marry, that I was special, a true beauty and a smart woman. We almost lived together (at his place) during 3 weeks. i was the absolute perfect woman, the "woman men can only dream about" he said several times.

And one day, less and less messages. I ask him why and he tells me he doesn't feel anything anymore for me while he was declaring his love 48 hours earlier. When I ask for explanations, he gets angry, cold, tells me not to be desperate and to let it go. That he respects me enough not to ghost me but that he is incapable of explaining why he switched off. Tells me I am the perfect woman and that I must not blame myself. Wants to remain friends but I feel betrayed and I refuse : he gets even angrier.

Now I get to see him almost everyday at work. He acts like I do not exist. No talking, no interaction, even during common meetings, he avoids me, which is totally unprofessional.

Why ?