It's clear Dazai can't really take care of someone properly, you noticed It since both started dating.

Today he's taking care of you because you got sick.. he's been keeping you in bed the whole day.

He told you he was going to make something for you, so you waited for him until he came back with a bowl of soup.

“Look! I made you some soup so you can get better.” He said while showing you the bowl, and just as expected, the soup looks totally horrendous. It doesn't even looks edible..