Do not try to stop breast feeding suddenly. For a 22 month old infant, the quantity of mother's milk is hardly about 100 ml in 24 hours. It is mainly for mental satisfaction that the child wants to feed on breast. No harm is done to either of you. In fact, it is now an established fact that prolonged breast feeding reduces the risk of breast cancer
in the mother.
Regarding refusal of your child to take formula milk, you may substitute it with curd, custard, pudding, buttermilk etc. Although,as pediatrician
,it is ethically not correct to advise you but I have faced this problem in my day to day practice and with my own kids too, and have been able to solve it by following method: You may add some Bournvita or complan to alter the flavor and color of the milk. You can also try mango-shake or banana-shake.