You speak about this so well and sorry that you are going through this. Social anxiety can be crippling at times and people just assume you are being antisocial and want to stay at home but the feeling is entirely different.
I think although we are talking about MH more now in society, people still have a very reductionist idea of what certain conditions entail. Depression = sadness, ED= not eating , anxiety= stressed out. The fact is there is so much cross over between them. You can have psychotic episodes without being classified as psychotic, ED can cause you to have social anxiety due to the fear of eating in front of people etc. Particularly with depression, the feeling of not being good enough transfers to every part of life.
Acceptance by society is coming but I am not sure understanding is 100% there yet. MH is so complicated, unless you have experienced it, it is very difficult to fully empathise.
People still tell me things which will set off a day or two of not eating followed by bingeing (even though I have asked them not to mention weight loss, how their diet is going etc).
I know it is corny, but my mantra was to just complete each day.