Hate to say it, but you may need tubes.
One thing I would try first is allergy medicine. I've had a lifetime of ear problems. Both eardrums ruptured at 15 and the holes never healed. Ten years later I discovered that it was probably the result of untreated allergies to grass and pollen which caused my sinuses not to function which resulted in long-term damage. To this day, if I don't treat an allergy outbreak my ears will fill with fluid and become infected. Talk about crazy -- ear infections at 32...
My own daughter had to have tubes at 10 months because one of her eardrums ruptured. In our situation, we had no choice. She continued to have infections after the tubes but not monthly like they had been.
The following spring they started again and I started to notice that on days when I woke up needing a Claritin for pollen and mold, she was waking up with a runny nose. Started giving her children's claritin and we've only had one ear infection in 18 months. She's 3 now and I still hold to the rule of thumb that if I wake up needing an allergy pill she gets one too. Worst case, it stops the runny nose. Best case, I think it prevents her ear infections because the fluid doesn't collect in her ear.