Sadly, there isnt much Sylevon CAN do with a Timid Nature. Its notorious sets are being cleric and specs abuser in singles, while usually abusing specs or life orb in doubles. Of course, it should go without saying that a Timid Nature on a Cleric set is a terrible way to use Sylveon, as Sylveon values every bit of bulk it can get to even try to compete with its Fairy friend, Clefable.
However, with a Choice Specs or Life Orb set, a Timid Nature could potentially be used if your team is concerned with certain speed tiers / other Sylveons, but the damage output from Sylveon is considerably weaker to one with a Modest Nature.
It would be best for you to breed another one. I will flat out say Timid Sylveon sucks.