MVC and respecting SOLID - php

Question

Just about a year ago I started creating web applications using the MVC design pattern. I started my journey with these series which provided me with some handles to create my own MVC application. Very basic, but straightforward.
Then I stumbled upon the S.O.L.I.D. principles defined by Robert C. Martin. Just by learning each principle apart I get how I could write maintainable code for the future. That's when I found out I have been breaking all 5 principles on a daily basis, but just because my code works I didn't try to respect them at all. So why not combine MVC with SOLID? This presentation by Stefan Priebsch gave me some insight on how to mix them together. Stefan proposes to create a single Controller for every single action that needs to be taken. That makes sense, it would result in clean, easy to read and maintainable code.
Now onto my problem. I've got an .htaccess file that does the URL rewriting. For example: http://website.com/user/create would create a user and http://website.com/user/email would send a new user an e-mail with account information. Both URLs go to the 'user' controller and execute methods 'create' and 'email'. Now this violates the Single Responsibility Principle. The 'user' controller would both have a function to create AND to email a user. It would be best to change the code and create two controllers:
class CreateUserController extends Controller {
public function create() {
}
}
class EmailUserController extends Controller {
public function email() {
}
}
This would mean that my URLs would be http://website.com/CreateUserController and http://website.com/EmailUserController. But that is not what I want right? /user/create would lead to CreateUserController and /user/email would lead to EmailUserController. How would I do something like this?
My router
This is the router I use. $url[0] is the controller and $url[1] the method within that controller.
class App {
protected $controller = 'home';
protected $method = 'index';
protected $params = [];
public function __construct() {
$url = $this->parseUrl();
if(file_exists('../app/controllers/' . $url[0] . '.php')) {
$this->controller = $url[0];
unset($url[0]);
}
require_once '../app/controllers/' . $this->controller . '.php';
$this->controller = new $this->controller;
if(isset($url[1])) {
if(method_exists($this->controller, $url[1])) {
$this->method = $url[1];
unset($url[1]);
} else {
header('location: /home/error');
}
}
$this->params = $url ? array_values($url) : [];
call_user_func_array([$this->controller, $this->method], $this->params);
}
public function parseUrl() {
if(isset($_GET['url'])) {
return $url = explode('/', filter_var(rtrim($_GET['url'], '/'), FILTER_SANITIZE_URL));
}
}
}
My base Controller
class Controller {
protected function model($model, $data = []) {
require_once APP . '/models/' . $model . '.php';
return new $model($data);
}
protected function view($view, $data = []) {
require_once APP . '/views/' . $view . '.php';
}
}