I found things got much better for me once I stopped masking my symptoms around my friends. I told them everything from how I felt in public places to what makes my symptoms get worse. They have become much more supportive and understanding than I imagined.
I sent them many links about PCS (even neurotalk) so they could understand what I'm going through. I guess it depends what type of relationship you have with these people.
One barrier with a friend was that she didn't understand the sitting in a quiet room alone for recovery. She always thought I needed to get out and be in the sunshine and with my friends. I found it very irritating but soon realized some people just don't understand certain things until they've experienced it themselves.
In some ways, PCS has helped me realize who my real friends are