Workers comp denied my surgery saying injury predates employment - employer is backing up the insurer's story

I work warehouse jobs and hurt my lower back at work about four months ago lifting a pallet that shifted unexpectedly. I reported it the same day, filled out the incident report, went to the company's occupational health clinic. The doctor there noted muscle strain and gave me restrictions. I followed all the steps correctly.

Fast forward to last month - the MRI showed I actually have a herniated disc that the initial evaluation missed. The comp carrier is now denying surgery authorization, saying the herniation is a "pre-existing degenerative condition" that wasn't caused by the work incident. My employer's HR rep has been saying things to me that sound a lot like she's supporting the insurance company's version of events, not mine. I'm starting to feel like they're coordinating.

I'm in Ohio. I don't have an attorney yet - I keep hesitating because I don't really understand how comp attorneys get paid or whether the claim is big enough for one to take. The surgery estimate is around $35,000 and I've been out of work for four months. Is this the kind of situation where an attorney actually makes a difference or do people handle this themselves?