My relationship ended and I don't know why?

My boyfriend and I have been together for five months. Everything was great. It was perfect. He was always so happy to see me and would spend the whole day with me and we would be disgustingly adorable.

Then after he got home from work the other day he asked me for a video call. As soon as I answered and he saw my face he got the happiest look on his face and his eyes welled up with love. Nobody has ever looked at me like that and I felt so special.

He said he loves me so much and even went as far as saying he could see us getting married someday after we meet in real life. But... until we live closer he just can't handle the distance anymore... and he broke up with me.

Today was the first time I woke up with no cute, lovey texts. The first time he didn't message or call before he had to go into work. The first time he didn't message me as soon as he got home. The first time he didn't tell me he loves me. The first time he didn't message me til he passed out...

I feel like a huge part of me died and I feel so unbelievably broken.

I just don't understand what happened. We were so happy. We gave our "cringelovers" friends a run for their money of being the most adorable couple. He's everything I've ever wanted and it's my first time legit being happy in a relationship in 12 years.

iunno what happened. please help ;-;