In many Tweek x Craig break up fanfics, one common reason could be miscommunication. Tweek's constant anxiety might make it hard for Craig to fully understand his needs, and Craig's laid - back nature might seem like indifference to Tweek. Another factor could be external pressure, like the opinions of their friends or family in the fanfic's universe not being supportive of their relationship, which gradually wears them down.
Yes, the Komi manga is over. It might be a bit sad for fans, but that's how it is. Sometimes, all good things must come to an end, and this was the case for the Komi manga.
There was this couple. The guy planned an elaborate beach proposal. He had a big sign made that said 'Will You Marry Me?'. Just as he was about to pop the question, a huge wave came and swept the sign away. His girlfriend was so distracted by trying to save the sign that she didn't even notice him getting down on one knee. When she finally realized what was going on, she was so flustered that she said no. They later broke up because they couldn't stop laughing about the whole situation and decided it was a sign from the universe.
Well, it often depends on the specific circumstances and the characters' personalities. Maybe have an honest and calm conversation to explain your feelings clearly.
Well, in manga, a common way could be to have a serious face-to-face talk in a quiet place. Another option could be to send a message if it's too hard to do it in person. But it's important to be honest and clear about your intentions.