500 and 503 errors HELP

Hi
I started to have many 500 and 503 errors on my admin panel. I didnt install new plugins; it just started from nowhere. Every time I try to edit or add new post, it takes ma about 30 minutes because errors come up and my website is not working. Godaddy (my hosting) told me that there can be problem with connection to database (opens but doesnt close). Can you tell me how to fix this problem? Du you have any ideas?