Why has my blog disappeared?

I was trying to get the bar under my header to be centered, and so I changed the dimensions of “Column 1” under my Thesis design options. (I changed it from 680 to 800.) Suddenly, it gives me a bunch of error messages and refuses to work under Thesis anymore. (All I get is a blank screen with a bunch of ……………….. lines)

I switched to a new theme, and it works again: https://www.chocolatecoveredkatie.com

By any chance, can a tech-savvy person help me figure out why my blog is suddenly not working under Thesis, and how to fix it? I’ve been googling, but I can’t seem to figure out anything. I would appreciate help so incredibly much!