Sorry you are flaring after such a long remission.
How much Asacol are you taking a day? 4800 mg (6 tablets) is the max dose per day to be used when flaring and then taper down to a maintenance dosage once in a solid remission. 1600 mg/day is not likely to get you out of a flare. Would be best to get rectal meds too -- treat from both ends as Quincy always says.
There is a generic Asacol now that may be less expensive
Hope you return to the promised land of remission soon!