Admin panel has lost formatting since update

Since updating to the newest version of WP, I have lost all formatting in the admin panel. Instead of having a sidebar, it’s now contained in the top 1/2 of the panel. Then when I scroll down, the content of the selected section eventually appears, however the panel that was at the top now appears on the left side and cuts off the left hand side of content. EG if I click into ‘update plugins’ I can’t read the first few words of each sentence, neither can I click the tick box to update the plugin. Can anyone shed some light on how I might be able to fix this please?