I Have Been Diagnosed With Fluid In The Back Part

I have been diagnosed with fluid in the back part of my ear. It caused me to have some hearing loss. I am 80 years old. It happened after a bad cold. I was given antibiotic drops, that didn't work, then I was given 5 days of oral antibiotic but I still have the fluid a few weeks later. Will this finally clear up on its own or do I need more tests or more antibiotics? Should I have another hearing test? I wear a hearing aid in the other ear but before this happened the ear with the fluid did not need a hearing aid.
Thanks.