Update: I think I'm really going to have to quit this health kick.
My roommate has been complaining recently about the noise at night, so I've been trying to return the book to the Library, but every time I go back into my room it's resting on my pillow. I don't want my roommate to move out, so I'll keep trying.
This system to prevent Library books from getting lost is really a bit of a pain, but I do commend the librarians for the actions taken. It is their property after all. I just wish they'd take it back.
I suppose I ought to go have another try, and maybe eat my lunch outside today to get rid of the taste of curdled food.

@Georg Potookig, are you sure the curdling is just limited to food? From what the smudged pen marks on my arms are saying, last night (while I was looking for the missing pages in my notebook), I found page 164 about 2 feet from your door. This doesn not seem worrying, apart from the fact that it was covered in grey mouldy patches and began crumbling away as I touched it. Thankfully, I was able to rewrite the information into my journal, but the large pile of dust is both unsightly and worrying.

Where did you find that Self-Help book? If you can't return it, perhaps we could have a look at the effects of the exposure to it? Does anyone else have copies of this book, or has Georg found a limited-edition book of doom? I'm no good with any of this psychic stuff, but I appreciate the value of the scientific method and analytical collection of information!

(Although, I'm a bit worried to go near your dorm again. Page 164 had a lucky escape.)

H.H

You know, @Harper Hiraeth, I'm NOT so sure the curdling is restricted to food. There have been some odd smells floating about the place recently, but until now I've simply been putting them down to the decomposition of my roommate's latest... project. In fact, it probably is that too, but she has also been complaining about the increased rate of decomposition. Perhaps that's the book's doing.
Apart from that, my belongings are often covered in grey mould, so I wouldn't worry.
I found the book in the library, on a table in the fantasy section. I probably ought to have checked whether it really belonged to that section after all, as I was assuming someone had took it from elsewhere.
Any help concerning the book would be much appreciated! I'd love to find out more about it, preferably in a way that ends with it no longer in my possession.
(The dorm is safe -mostly- so feel free to come by any time to take a look.)

Okay, I'm right outside your dorm, @Georg Potookig. I've left my notebook in my room for obvious reasons, but I have a tape recorder so I can update it later (at least, if I remember). If the situation gets dire, I have a pack of chalk and a book of protection runes. I mean, it would help if I knew how to use them, but improvisation is key!

I stopped by the library (well, the place according to my notebook that was the library) to grab a book to act as a control, but I asked the librarian about any other books with unusual effects. Apart from dead silence as the telepathic message was communicated to my brain, learning and acquiring information seems to be the main side effect, with any books with harmful effects usually kept separately from the main collection.

The main plan of action could be to take note of any changes that have happened in your room, before finding a controlled environment to compare the effects of the Self-Help book and our control. I must say this now, every fifteen minutes you should tell me who you are and why I’m here. The tape recorder helps, but I don’t want to rewind it and miss anything important.
Don’t worry about your problems; let your problems worry about you!
H.H

Finally, I have found my way back to the non-virtual world; it seems computers aren't really my thing, so I must find another way to secure the Mindscape and its secrets. I have placed all of the warding I can at my current level of mystic strength upon it, but I am still seeking new sources of protection to apply.

Unfortunately, my fears of this knowledge wreaking havoc upon our dimension seem to have been realized; the "Self Help" book @Georg Potookig and @Harper Hiraeth have come into contact with could possibly have been stolen from one of the tree shelves in the Mindscape. I am currently trying to gain access in order to see if any books are missing, but all of the spells I have cast make it difficult for even me to enter.

If this book is really what I think it is, it may have "latched" onto one or both of you, @Georg Potookig and @Harper Hiraeth, which could hold dangerous connotations. Whether the latch was initiated my the thief or the original spirit, uncontrollable rotting could be but one of the eventual side effects, so be on the look out for any seemingly prophetic hallucinations, dizzy spells, or any other odd sensations. Also, I would try to decipher whatever words were scratched out on the book; they might be essential to understanding this whole situation.