Laser or LED based near infrared does not make a difference. The light wave is the same. Laser just means the beam of light is narrow. Problem is there is only so much light energy the tissue can tolerate. My PT has a laser based light therapy system that can be set to different wavelengths. The LED based systems have LEDs with the specific wavelength fixed with a small variation. In LEDs, 660 nm, 830 nm & 840 nm wavelengths would be something like 655 to 665 nm, 825 to 835 nm, and 835 to 845 nm. In Laser Diodes the specific wave length is achieved. The research does not show a difference in therapeutic value.

The laser is actually a Laser Diode as compared to Light Emitting Diode. The difference is primarily the lens and focus of the light. The technical differences would not make a difference in a therapeutic situation. The effective use of LED is within 10% or less of Laser Diode. If you needed to aim at a very small target, Laser would be better. But, the therapeutic use of near infrared light therapy is over a large area so the narrow focus is not necessary.

It looks like there is some selling the sizzle at Kahn's clinic.

The key issue I think you need to deal with is the risk level of impacts. Your startle response likely causes more G force than almost any of these impact that are causing your concern. Even the G force of your startle head jerks would be well below the threshold of injury unless you were jerking your head back and forth repeatedly.

You may benefit from some touch desensitization training. This would be something like sitting or laying with your eyes closed as someone touches you at random spots on your head and neck. Then, over time, that contact force is increased from a finger touch to a finger tap to a finger snap to a drop of an empty plastic water bottle on your head. Some of these touches would be without warning and some would have a warning. "I'm going to tap my finger on your head." This would be a sort of phobia conditioning program. A phobia specialist could lead you through this.

The same could be done with sounds to reduce your sound triggered startle.

EMDR is for PTSD by attempting to separate the memories from the response. I don't understand how it can help you with anxiety. It was offered to me after I was assaulted combined with some mental reprogramming to see the assaulter's position.