To put it simply, I'm looking for manga/novels with a protagonist that deals with extreme social anxiety as a result of a learned fear or learned feeling of inadequacy.
For example, the protagonist of Kimi to Tsuzuru Utakata was isolated by her classmates since she bullied one of them. However, she doesn't know how to deal with people anymore and started avoiding contact with people altogether as she fears that she might get into the same situation again.

I don't have a lot of preferences other than that I don't want Shoujo, Josei or Yaoi. (Yuri is fine)
And preferably it's in a modern day or sci-fi setting.

Thanks in advance!