Sorry for the trouble, losing blog posts is definitely a terrible feeling.
Where editing your blog on desktop is concerned, you'll want to go to the blog page in your editor, and click the Blog page on your Pages tab. The New Post and Draft buttons will be on the bottom right.
In regards to the missing posts, however, you'll want to contact support directly, as that's absolutely something they'll want to see live with you, so it can be cleared up ASAP.
