Unfortunately what you did, you altered "page.php" file which is used for every new page you make through admin panel. You need to understand that in first place. Page.php is template used for every new Page you make in admin panel, single.php is template used for displaying a single post, index.php of course for front page.
So the best way is to design your page.php in a way that is okay for every new page you create in Admin panel (ex. About me). It should be similar to index.php. The best way is just to copy everything from index.php and just alter it to suits your needs. Then you can easily write whatever you want, and it will be shown.
Currently it cant do that, cause you altered it to just show posts, and now every new page you make will be the same, just posts.
What you need to do is actually easy. You just need to make a new PHP file inside of your theme folder, ex. blog.php, and whats important is this line of code
Template Name: Blog
Rest of that file can be the same as your altered page.php which means you can just copy paste it. Then go to Admin panel, Add new page called Blog (or do it for the one you already have). You should now see your custom template name appear under the “Template” pull-down in the Page Edit screen, as indicated in the pic below by the green arrow.
When you have your blog.php up and working correctly, you should redesign page.php (note that once you have blog.php, you can clear your query_posts code from page.php)