I have been through Neurofeedback twice, once when I was diagnosed with ADHD and recently for severe depression from post menopause.
This last time I was given a device to rent called an Alpha-STIM which is specifically for anxiety, depression and/or insomnia. I noticed a difference after my first 60 minute session. I was allowed to rent it weekly and then bought my own device. I use it 4-5 days a week for 60 minutes at a time because it just makes me feel good. It sends very low impulses to the brain which increases Alpha Waves in the brain (the calming waves).
For me it is about occasional depression/insomnia, but I imagine it would be excellent for anxiety.
I would inquire to the place you get neurofeedback and ask about it. I would recommend this as you already do
neurofeedback for your son.
I love my instant feel good device 😊