laravel custom login error validation - laravel

Question

I'm doing multi authentication in Laravel in user login form the error validation is working but in my company login form the error validation is not working . please help me I'm just new in Laravel and I'm just a student. Sorry for my English
this is my code in login
public function login(Request $request)
{
$this->validate($request, [
'email' => 'required|email',
'password' => 'required'
]);
if (Auth::guard('company')->attempt(['email' => $request->email, 'password' => $request->password], $request->remember)) {
return redirect()->intended(route('company'));
}
return redirect()->back()->withInput($request->only('email','remember'));
}
and this is my form where error must show
<div class="form-group row">
<label for="email" class="col-sm-4 col-form-label text-md-right">{{ __('E-Mail Address') }}</label>
<div class="col-md-6">
<input id="email" type="email" class="form-control{{ $errors->has('email') ? ' is-invalid' : '' }}" name="email" value="{{ old('email') }}" required autofocus>
#if ($errors->has('email'))
<span class="invalid-feedback">
<strong>{{ $errors->first('email') }}</strong>
</span>
#endif
</div>
</div>

Answer 1

instead of:
return redirect()->back()->withInput($request->only('email','remember'));
use this:
$errors = new MessageBag(['password' => ['Email and/or password invalid.']]);
return Redirect::back()->withErrors($errors)->withInput(Input::except('password'));
also add this to the top of your controller
use Redirect;
use Illuminate\Support\MessageBag;
use Illuminate\Support\Facades\Input;