Create a new website. Choose whatever category you think fits your blog best and whatever theme you like. You can just choose the free plan unless you want a custom domain for whatever reason.
Click Settings on the sidebar.
Then click import at the top of the page and go to “Other Importers”
From the list that appears, choose “Tumblr”
You should be asked to log in. Once you do, all your blogs will appear in a list.
Simply click “Import this blog” and every single one of your posts, including all of their tags, will be imported into wordpress. It will take a very very long time but it should work. You will now have a wordpress website that contains an exact copy of your blog. I would recommend changing it to “Private” in the main settings if you don’t want people thinking that it is active, because at least I know I won’t actually leave tumblr unless it really does shut down, which I don’t think will happen.