The dosage you gave isn't translating correctly. How many milliliters (ml) did you give of the solution and how much does your rabbit weigh?
Ivermectin overdose can not be reversed. All you can do is provide supportive care in the form of fluids and syringe(no needle) feeding if your rabbit is alert enough to chew and swallow without difficulty. This needs to be continued until your rabbit is eating well on it's own. When syringe feeding, always do it slowly and carefully to allow the rabbit time to chew and swallow the food or water. If you syringe food or fluids too quickly into the rabbits mouth, this poses a greater risk of the rabbit aspirating the contents.
If your rabbit is unconscious or too lethargic, DO NOT syringe feed anything as this poses a risk of aspiration of the contents. If you have a vet that is competent enough to administer an IV correctly to a rabbit, then I would suggest having that done, as this will help your rabbit to not dehydrate, as well as the fluids helping to flush the medication from the body. If an IV is not possible, subcutaneous fluids from the vet may be helpful, ,but that will depend on how severe your rabbits condition is.
If your rabbit isn't extremely lethargic or unconscious, there is a good chance your rabbit will recover if you provide the necessary supportive care that is needed until your rabbit is completely better.