L.S.
she can have cow's milk. You aren't being selfish. For goodness sakes you've breastfed for 17 months. I BF for 10 and half months. Just start introducing it in sippy cup or bottle. It may or may not have to be warmed up. My son liked his cold. We actually went from breast milk to formula for a time and then went to regular milk. Don't worry so much, you did a great job with breastfeeding. If you want to be done, be done. She may be a little annoyed and cry, but see if you can distract her with cuddles, bookes, etc. It is sad to be done but sooo liberating!