I think you're having a hard time because you're showing so many different kinds of work. That's basically a retrospective, and would be served by a very broad title. Like "Photographs by ______." Unless you can think of a more specific common thread tying them all together. The fact that they're black and white is not interesting enough ...

I write a different statement for each body of work I produce. I wouldn't know how to write something coherent that covers the experimental stuff I'm doing now, the landscapes I did fo the last many years, and the street pictures I did while in school.

If you get someone to write it for you, I think you'll have an easier time with someone who knows you well and really likes your work. It will likely be a tough job no matter who you hire. I just did a similar writing assignment for a friend—it took over a dozen drafts, because it's basically ghost writing for someone about the thing that's most important to them.