Store the secrets on a local machine:
mkdir -p ~/.secrets
touch ~/.secrets/my_secrets
chmod 600 ~/.secrets/my_secrets
cat << EOF | gpg -c -o ~/.secrets/my_secrets
export SOME_SECRET_VARIABLE=some value
export ANOTHER_SECRET_VARIABLE=another value
EOF
Inject the secrets into a terminal ENV (anytime):
$(gpg -q -d ~/.secrets/my_secrets)