Oh you poor thing. I have an 8.5 mth old and could almost have written your post word for word! It's NUTS. And some days I get a nap and cope well and other days I feel like I'm barely living. I never BF to sleep but thought it was a co sleeping issue. Recently I went to an ABA group and the women there suggested that I BF DS up through the day - as in every 1.5 hours or when you think of it. And after a few days, they thought he should be sleeping better. I thought "yeah whatever' but anything is worth a go...
and it really worked for us! Actually, from the first night he only woke once rather than a dozen times. But they had warned it could take a few days. (Well it worked until he got sick. Now it's anyone's guess).

Anyhow who knows, but it's worth a try. Definitely, don't switch to formula in the hope of longer sleep! There are so many reasons why that one is a myth (sorry to the pp) - but especially because your milk supply is important if you want to keep BF.

Having said all that, it does sound a lot like separation distress rather than food related. And I have no clue what to do there...because it's driving me nuts myself. I hope you're going ok though and will follow the posts to see if I can pick up some advice too GBH

PS Do you have Elizabeth Pantley's "No cry sleep solution" book? She has some advice for the weaning off the breast/sleep association.