I was diagnosed with seasonal/environmental allergies. For years, it was well controlled with chlorpheniramine. The allergies are bad now but the symptoms are constant. What should I do?

Several Options. If one is having increased seasonal allergy symptoms and otc meds are not helpful see your pcp. In general the treatment for allergy symptoms include avoidance, medications ( antihistamines and nasal steroids/antihistmines) and allergy vaccines. If your pcp can't help or one's symptoms are that severe they should might suggest a visit to an allergist.
Need more treatment. Sometimes you need to add another type of medication, such as a prescription nose spray, or think about having shots to lessen the symptoms. See your allergist or ENT for more discussion.
All year allergies. Seasonal allergies that have now morphed into perrenial symptoms could be indicative of the development of new allergies or the progression to a more chronic sinus issue. Use of nasal steroids can oftentime be helpful, but seeing an allergy/sinus specialist might give you the best long-term relief.
?question?other RX. If you are looking for other rx suggestions there are several available, the 1/day meds like allegra(fexophenadine) or claritin(loritadine) work fine in some & are available otc. You may want to do an environmental audit: any dust/smoke/perfume /fume products will aggrivate & feel identical to allergic triggers in some.With these issues avoidance is the key to improvement.