Flutter Grid View Stick to Bottom inside a List View

I am trying to create an application for university project using flutter. My current code is as follows.

import 'package:flutter/material.dart';
import 'package:mathappcd/constants/widgets_constants.dart';
import 'package:mathappcd/screens/sectionA.dart';
import 'package:mathappcd/screens/sectionB.dart';
import 'package:mathappcd/widgets/app_bar.dart';
import 'package:mathappcd/widgets/square_btn.dart';

extension ContextExtension on BuildContext {
  bool get isSmallScreen => MediaQuery.of(this).size.shortestSide < 500;
}

class HomePage extends StatefulWidget {
  const HomePage({Key? key}) : super(key: key);

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
  }

  @override
  void initState() {
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: const CustAppBar(
        title: "App",
      ),
      body: ListView(
        children: [
          const SizedBox(
            height: 300,
            child: Center(
              child: Text("Graph"),
            ),
          ),
          GridView.count(
            shrinkWrap: true,
            padding: const EdgeInsets.all(WidgetConstants.sqrBtnPadding),
            mainAxisSpacing: 20,
            crossAxisSpacing: 20,
            crossAxisCount: context.isSmallScreen ? 2 : 4,
            children: const [
              SquareBtn(
                text: "A",
                directTo: SectionA(),
              ),
              SquareBtn(
                text: "B",
                directTo: SectionB(),
              ),
              SquareBtn(
                text: "C",
                directTo: SectionA(),
              ),
              SquareBtn(
                text: "D",
                directTo: SectionB(),
              ),
            ],
          ),
        ],
      ),
    );
  }
}

And it gives the result like this.
But I want the grid view to stick to bottom as in this image.

I achived this using a Column and a spacer but then when the screen height isn’t enough it gives an error like this. I have tried many other ways but failed to get the exact result I needed. I want it to be responsive and also the whole wcreen to be scrollable when the screen height is lesser than the height of SizedBox (Graph) + Grid View.

Please help! Thanks in advance.