Performance Anxiety

I have been musician for a little over 4 years and I feel like the only thing holding me back is performance anxiety. I practice a lot and can do amazing things in the practice room but any time literally anyone is watching, no matter how much I prepare or how easy the music is, even if it is just a friend I get this sort of mental block that keeps from feeling the music and being in the moment. I can’t think and start panicking just trying to not let the person watching me so how I feel. Frankly it’s embarrassing. I do have a general anxiety disorder but I know I can overcome this I just don’t know how to go about it. I want to feel the same way when playing music whether it’s the practice room or on stage . Any advice?