WordPress running slow

Hi everyone,
Could someone please help me , I am new at wp. It’s been a couple monthes now and I don’t know how much more I can take !
My site http://www.christianrockangel.com is running pretty fast as it did from the beginning. The WordPress side of the site is getting slower and slower everyday. When I do a post everything is fine until I hit publish or preview or when I go back to edit post, it’s much slower than when I am on the site, navagating around. It must take 20 seconds or more each click until the wp loads up. The site itself loads in about 3 sec. This makes my tweeking of the posts very time consuming. Does anyone know something I can do to check to see if there is something wrong ? Or does anyone know what might be going on ? Thanks so much,
CRA1