Elimination diet questions?? (Long)

Hello, 

 I have a 5 mos old who is having trouble digesting sucrose and lactose. So where the story begins it...... shortly before she was 4 mos she had blood in her stool that landed us in the ER in a panic. The ER doc said that she was most likely allergic to dairy and that I should eliminate all dairy from my diet, wait 3-4 weeks and we should see improvement. So it has been about 6 weeks now with NO dairy of any kind. I have been reading food lables and been extremely careful with my food choices.  Just this week we went back to the pedi for her 5 mos check up and they checked a stool sample and it showed she still has blood in her stool (not visible just tested posative by the nurse). So this time around they drew blood and collected another stool sample that was sent to the lab to check for a reducing substance to see if she is digesting correclty.  the out come of the blood work is that she is only "allergice" to Egg whites not lactose or sucrose. However it showed that she is not digesting sucrose or lactose well and  if I want to continue breast feeding I have must eliminate both from my diet.  I am more than willing to remove them I just dont know where to start.  we have started weaning her to nutramigin formula by putting half breast milk and half formula in bottles and slowly increasing the formula. she has done really well with this and we are on day 3 and she is now taking 2 oz BM and 3 oz Formula each feeding.  I am pumping each time she eats so that I DONT loose any of my supply.  The Pedi thinks that making the majority of her diet formual will help her tummy and GI track heal as well as give me time to get the sucrose out of my system.  I do not want to give up on breast feeding at all. I enjoy my time with my daughter and am willing to give up what ever food it takes for her health.  Do any of you moms have any experience with eliminating a food or foods from your diet for the baby??  Please help.  Thanks so Much!!!