Going to prescribed Physical Therapy to learn to walk again after an accident. I have the best plan Aetna has to offer at my company, been to 10 out 60 covered sessions and yet they are saying Optum Health is denying my claims going forward. What can I do?

Situation: Today I was told that even though I need the care, I’m going to an in network provider, the doctor and PT says I need to go, and Aetna (my plan has a $100 deductible which I’ve met, 10% co-pay) covers 60 sessions per year, some other company called Optum Health is denying my claim after my session tomorrow. The insurance company then said I can appeal but I have to wait for the denial letter to arrive first which may potentially cause delays in treatment. Wtf is going on and how can I get this sorted ASAP?

Background: (31/F/USA) I was hit by a distracted driver while on a bike on a bike path a couple months ago. I have a fractured foot along with a crush injury resulting in severe nerve, tendon damage, and loss of feeling in the front of my foot. I’ve been going to physical therapy twice a week for 6 weeks now, and my doctor plans to give me new prescriptions for it every 4 weeks until I recover. I can’t physically walk on my own yet but I’m seeing some improvements thankfully and need physical therapy to help with this.