Personally, I would say possessive. As the person in question seems to be quite possessed about the person that the passage has been written for. If someone had sent this to me, I would also feel quite scared, as this is something that also seems to be quite threatening. If this passage was written after two people had split up, then It may seem quite bitter, but it doesn't seem that at the minute. Some people may see this as thoughtful, but general, something that is thoughtful is something that is nice, and appreciated, and this is something that this passage may not be.
