Wow, I had the exact same situation, and at the same point in time, I couldn't take the elimination diet anymore. I couldn't eat dairy, soy, eggs, nuts, peanuts, fish, or shellfish. At 4 months post-partum I only weighed 109 pounds. So, I had to put my daughter on the hypoallergenic formula as well. That stuff is nasty. I tried to wean her off the breast milk as you're doing, but I didn't have much success. I eventually just switched over. She wasn't happy at first, but she did get used to it and enjoyed taking her bottles before too long.
Not to get you down on your decision, but I personally regretted mine. If I had to do it all over again, I would have tried to hang in there for another couple of months or so. However, I would have had to cook for myself more and get a handle on cooking for my special needs. It is tough though. And impossible if you're eating out!
My daughter did fine with milk and soy when we introduced those foods to her when she was older. Now she is a 6-year old with a huge appetite!
Good luck!
C.
www.littlebitquirky.blogspot.com