Make my set proxy script better

Below is my bash script to setup a proxy, I am by no means an expert in bash. I suspect there is a better way to write this, any tips would be appreciated.

Adding more details to satisfy stackoverflows requirement. Is there a better way to do nested while-loops and if-statements?

#!/usr/bin/env bash
set -e

#Set Proxy
shopt -s nocasematch
while :
do
  echo ""
  read -r -p "Is a proxy required to access outbound http/https sites? [Yes/No] " input
  case $input in
    [y][e][s]|[y])
      printf "\nPlease enter your proxy url"
      while :
      do
        printf "\nExample: https://proxy.example.com:8080\n"
        read -r -p "Proxy: " proxy
        if [[ $proxy =~ ^(https?)://[a-zA-Z0-9][-a-zA-Z0-9.]{0,}[a-zA-Z0-9](.)[a-zA-Z]{2,}$ ]]; then
          if [[ $proxy =~ ^(https):* ]]; then
            proxyport=443
            echo "Proxy Port: $proxyport"
          else
            proxyport=80
            echo "Proxy Port: $proxyport"
          fi
          break;
        elif [[ $proxy =~ ^(https?)://[a-zA-Z0-9][-a-zA-Z0-9.]{0,}[a-zA-Z0-9](.)[a-zA-Z]{2,}:[0-9]{1,5}$ ]]; then
          break;
        else
          printf "\nERROR! Please enter a fully qualified domain name starting with \e[1m\e[31mhttp://\e[0m OR \e[1m\e[31mhttps://\e[0m";
        fi
      done
      printf "\nIs the following Proxy information correct?\n"
      if [[ -z "$proxyport" ]]; then
        proxyurl=${proxy%:*}
        proxyhost=${proxyurl##*/}
#       proxyurl=$(echo $proxy | cut -f1 -f2 -d:)
        proxyport=$(echo $proxy | cut -f3 -d:)
        echo "Proxy: $proxy"
      else
        proxyhost=${proxy##*/}
        echo "Proxy: $proxy:$proxyport"
      fi
      echo "Proxy Hostname: $proxyhost"
      echo "Proxy Port: $proxyport"
      while :
      do
        read -r -p "Is it right? [Yes/No] " yn
        case $yn in
          [y][e][s]|[y])
            break;;
          [n][o]|[n])
            printf "\nStarting Over...\n"
            break;;
          *)
            printf "\nERROR! Please enter Yes OR No.\n";;
        esac
      done
      if [[ $yn = ^y ]]; then
        break
      else
        printf "\nStarting Over...\n"
      fi;;
    [Nn][Oo]|[Nn])
      printf "\nMoving on then\n"
      break;;
    *)
      printf "\nERROR! Please enter Yes OR No.\n";;
  esac
done
shopt -u nocasematch