Acquiring a rope would obviously not be "too suspicious". For quite a long time, people have used a technology known as "bags" to transport items. Most people use bags on a daily basis. Even someone who is supervised by their parents (but is over 18?), probably frequently uses a bag. If the rope were put in the bag, the rope would not be visible while being transported to your room.
Of course, this isn't about the rope. It's about looking for reasons why hanging isn't possible. Which is natural, because it's a very frightening prospect.
Belts and cloth both work just as well as rope. Even though it is brought up on this forum endlessly, nobody actually ever lacks the material resources need to hang themselves. It is a common method partly because it is universally accessible. What it comes down to is that death is frightening, and it typically requires extreme and immediate pressure for someone to take their own life.
Partial hanging is in the same category as intentional substance overdoses in that it very probably will not cause death. It's a suicidal gesture rather than an attempt that anyone, upon reflection, will have any expectation of succeeding.
