Paying over 7k before/2k after insurance for chest tightness

Hi everyone. I live in the US in California.I have a healthcare plan with a 1.5k deductible and 10% copay in-network.

Last week, I started getting chest tightness and soreness in my shoulders. After not going away for 20 minutes, I decided that I could not rule out heart issues and I needed to go to the emergency room. I could move enough to drive, so knowing the cost of ambulances, decided to drive myself.

I was there for about 20 minutes. They took an EKG and checked my vitals. They also provided the option of taking a chest X-ray to check my lungs which I accepted. The doctor thought that it was a back issue since I had been videogaming all day. I drove back, so sore I could barely move but glad I had gone.

So now, I get an $8000 bill in the mail.

After my deductible and copay this is still around 2.5k. This seems ridiculous. I’m questioning my decision to have gone.

I already wrote a letter to my insurance telling them that I don’t think the price correlates to the services provided.

Is there anything else I can or should do? Or does this seem reasonable, for some reason I don’t understand?