Since I was a child, I’ve had these so frequently that they don’t really hurt me anymore. However, I’m curious what the experience is like for a typical person, as everyone says they’re painful but nobody ever describes the actual sensation. For me, it’s just a sense of pressure and losing my ability to hear. Whenever I tell people that, they give me annoying responses like, “Are you sure your ears aren’t just plugged?” and I’m like, yeah, I’m positive. I’m asking because my visit to urgent care was a total disaster; the doctor was convinced I was just acting tough and wouldn’t listen when I said I didn’t need pain meds, even though he mentioned grown men cry over infections like the one I have. I just want my hearing back in my left ear.
I have only had one, and I’d rate the pain at a 4/10. Don’t get me wrong, it was painful, but my perspective is skewed because I deal with cluster headaches. The most irritating part was the heavy pressure and the hearing loss, along with the tinnitus that never went away. It wasn’t just the pain for me, but the combination of pressure, deafness, and ringing.
I got them all the time as a kid whenever my ears got wet. Yeah, they hurt sometimes, but it wasn’t extreme pain—just very draining and uncomfortable because it was constant.
My middle ear infection was the single most painful thing I’ve ever experienced. I had to go to the hospital for the kind of painkillers that make a normal person feel totally spacey, and they only barely dulled the pain. Fortunately, the pain relief allowed the surrounding muscles to relax, which let it drain and clear up pretty quickly. Still, it’s at the top of my list for most painful experiences.
I dealt with intense ear infections as a kid. It felt exactly like having a nail driven into my ear.
There are several types of ear infections, and sometimes fluid in the middle ear is called an infection even if it isn’t painful or acutely infected. That sounds like what you’re dealing with, where the primary symptoms are hearing loss and a plugged feeling. A real acute middle ear infection can be incredibly painful, potentially rupturing the eardrum and causing bloody drainage. An outer ear infection (swimmer’s ear) is also extremely painful across the board. Finally, a true inner ear infection is usually painless but can lead to vertigo and permanent hearing damage, though those are rare in younger people. Edit: I just noticed you were diagnosed at urgent care. Yeah, they tend to call everything an ear infection. 
You might not even have fluid, just pressure in the middle ear. An ENT could give you a definitive answer. Source: I am a clinical audiologist.