What’s slowing down my site?

First off, I’ll admit I’m a newbie to stylesheets so I may be my own worst enemy. But I am toying with a site at Bessed.com and the more I tinker to get things the way I want them the more it slows down, with the home page taking 5 seconds or more to come in.

I used this Onef theme, which is an offshoot of the Blix theme, then I started monkeying with it so I could get a bigger search bar, lose the navigation bar, and have just a small image as the header. It still seems fairly simple to me but it has slowed way down.

I’m wondering if the header has something to do with it. All the themes I see use a background as the header where I’m just plugging in a single image instead, but that doesn’t seem like enough to slow it down.

I might be better off just hiring someone to create a theme along the lines of what I’m looking for, but if I can figure out how to NOT slow things down when I’m tinkering with the look, I won’t have to.

The Web host is Jumpline, who I use on other sites and like. I don’t thinkthey’re the problem; I think it’s the theme (and my messing around). Any thoughts would be appreciated.