Hi guys, thanks for your replies.

@elevatedsoul I do have a psychiatrist. Do you think I should call at this stage? I was planning to see how it goes today and call tomorrow if things don't improve...

@SFVQ My flatmate does know, but I don't think she even recognized I was getting worked up. When I say I was upset, I was upset in private. Publicly I held it together. The ironic thing is that the actual issue affects my flat mate much more than it affects me because I'm moving soon, so it is totally ridiculous that she is not dealing with it. When I was told about the problem by our landlord, I just couldn't let it go in my head, and I was really frustrated that my flatmate was taking such a casual attitude about it... I feel really manipulated, but I guess it's because I'm getting worked up.