To get into a BSN program you will need to take chemistry, biology, microbiology, and either a combined anatomy and physiology course or seprate classes depending on the school. I'm sure you probably already have a lot of the other basic classes completed since you're graduating with a B.A. in English. I to will be graduating in May with a BSN and have contacted the University of Kansas nurse anesthesia program. I will have to take elementary statistics, organic and/or biochemistry, an additional A/P class and physiology probably after I graduate. Your best bet would be to contact the schools you are interested in and find out what they require for sure.
As you already know you'll have to work in an ICU probably for a couple of years. Next you'll have to go through the process of applying to nurse anesthesia schools and jump through all of the hoops before you're accepted like: interviews, letters of recommendation, etc. Hopefully that will help you a little bit. I've found most of my information on this website and on the internet. Good luck!!