There is a name Tarah in the Old Testament (Exodus) so I would guess it is of Hebrew origin. It is said to mean "one who is banished" or "one in flight" - there is a reference to the name here if you would like a look (you have to read a few paragraphs before you reach the reference.
There is also a Malaysian word Tarah which means "to cut off" - I don't know whether that sounds likely to you? Otherwise, if the old Hebrew origin isn't right, the only other possibility I know of is that your name could be taken from the old Gaelic TARA, meaning "hill" which was the home of the ancient Irish kings. Tara has often been given to girls as a name in the 20th century, and your spelling could have been influenced by its similarity to the old Hebrew name SARAH.
There is also a Malaysian word Tarah which means "to cut off" - I don't know whether that sounds likely to you? Otherwise, if the old Hebrew origin isn't right, the only other possibility I know of is that your name could be taken from the old Gaelic TARA, meaning "hill" which was the home of the ancient Irish kings. Tara has often been given to girls as a name in the 20th century, and your spelling could have been influenced by its similarity to the old Hebrew name SARAH.