Hyperperfusion is a relative term. It just means you have more blood flow than expected compared to other areas. If your anxiety decreases, that part of your brain may demand less blood reducing the hyperperfusion.

You might check with an Amen Clinic and see if they will review your SPECT. They have reviewed more SPECT scans that anybody in the world.

HBOT is intended to try to increase blood flow by encouraging capillary growth.

Hypoperfusion just means reduced blood flow. Lack or loss of blood flow would be a different term.

What was suggested to treat the hypoperfusion ?

I think you are being impatient. The brain needs three things, Time, more time, and good habits (nutrition, sleep, behavior)