I don't think they automatically think it's all "in your head" but understand how you feel that way. Especially with the fibro. I find I often second guess what I'm physically feeling after all the stuff I went through before getting the fibro diagnosis.
You're still taking meds, right? Many meds have side effects and I still think the doctors wanted to get an idea if it's the meds causing the experience you had last night.
I'm very happy to know you're getting the medical attention you need.
Love,
Lenina