What is incumbent upon one who made a vow and swore by the Qur'an due to obsessive thoughts, then did not fulfill what he vowed?

The optimal cure for obsessive thoughts is to beware of them and pay them no mind. If you swore an oath and then broke it under the influence of obsessive thoughts, then there is nothing upon you, because you are in the position of one who is coerced. However, if you swore an oath and then broke it willingly, then what is obligatory upon you is an expiation for an oath for each oath, and similarly for the vows you made.