Heartbroken in Japan

I arrived in Tokyo late last night, I'll be here 7 days. This is my first solo trip and I booked it because my long term partner broke up with me suddenly a month ago and I thought this might help, but I cried the whole 10 hour flight and now I'm here all I want to do is sob. Its like the heartbreak is 100x more intense. I am on the other side of the world away from everyone I love, I feel physically ill with grief, and I'm so fucking lonely. What do I do? I just want to go home.