Stop listening to your mom and your mother-in-law and start listening to yourself. Weigh your options carefully, because once you stop breastfeeding, you can’t go back and change your mind. It is really a personal decision that you should read up on and then make up your mind.
Breastfeeding, if you choose to do it, should last at least 6 months but maybe even up to twelve. Breastfeeding provides antibodies that help prevent ear infections, respiratory infections, allergies, and diabetes sometimes. Breastmilk is easy for children to digest, so their digestive processes are often better than those who are bottle-fed. Nursing helps you and the baby bond. And, of course, breastfeeding is cheap and helps you lose the baby weight! While those last two are totally selfish reasons to breastfeed, they are reasonable to consider.
Formula, however, is a lot more convenient. You can use it in any time, place, or social situation. If you have older kids, it might be easier to warm up a cup of formula rather than breastfeed. You and your partner can share the feeding process and both bond with your child. You can drink, you can return to work without worrying, and you can gorge yourself on fish again.