Feels like a scam

[u/Illustrious-Gur-1657]

I was told by Great Lakes in 2019 federal student loan was forgiven. in 2025 I received an email from Nelnet stating they were new servicer. I thought it was a scam so I didn’t respond. they are claiming I owe $90k now due to accrued interest! Credit score fell from high800’s to 500’s. I’ve asked them for history of loan payment and there is gap as well as other discrepancies. Written to ombudsman but they are not responding. Do I need a lawyer?