Middle Earth as a Parallel Universe

[Lord of Angmar]

I have read Timeline, Squire, and I enjoyed it very much.

but if a parralel universe was created at all, wouldn't it be a world where Professor Tolkien had not written LotR?

Indeed there would be, Squire. In fact, strange as it may seem, there probably is a universe in existence in which the Professor did not write any of his books. However, there are possibilities for trillions and trillions of different universes, so a universe could exist where Tolkien or his works did not exist and a universe could exist where all of Tolkien's works are realized. Both can exist at the same time, as well as billions upon billions more!