Appeal process for Self Insured policy(Employer)

I’m not sure if I’m in the right sub but anyways:

I’ve been doing this treatment that my doctor recommended for 12 months. The insurance company paid 7 months then said their policy changed and they require progress notes plus preapproval before every session. The hospital or insurance company never sent updates and I wasn’t aware of this till this week. The hospital contacted me just this week saying to they’re going to file an appeal on my behalf and to sign the designated person auth form. This is how I found out I may owe for 5 months. the amount of money that I am potentially liable scared me, so I filed a complaint with my state.

I didn’t know but apparently, employer plans are self-insured plans and states don’t have jurisdiction over them. It goes under the ERISA laws and I was told I can file a complaint through the USDOL/EBSA but this is a complaint against my employer as a plan admin, NOT the claim processing entity(My insurance company).

I get it too, at the end of the day I should’ve been making sure the claims got paid. Ironically, I checked every month for 6 months and assumed it was going to be ok after .

My hospital also told me, they dont need pre-approval with my insurance co because their contract states they don’t.

My question, How do I make sure the hospital and the insurance company are working together so I don’t end up with this large balance? Are there any protections for me besides going through USDOL/EBSA or the normal appeal process? Am i worrying too much and should just let the hospital do their thing? What are my options at this point? How screwed am I?

Sorry about any grammar issue; English is my first language, I just suck at it.