L.B.
To those who do not support your breastfeeding your baby, say that the WORLD HEALTH ORGANIZATION recommends breastfeeding for AT MINIMUM ONE YEAR, preferably two and, beyond that, as long as both mother and child find it mutually rewarding.
Tell your sister that you think [shrimp/mushrooms/caviar/runny eggs/whatever] is disgusting, too.
Ask them: if they think breastfeeding at 11 1/2 months (or 14 months, 20 months, 28 months, whatever) is disgusting, how do they suppose you should handle diaper changes, potty training, clothing changes and bath time? Perhaps you (and your husband!) should withhold caring for your baby in these ways, as well? Then, tell them you will stop nursing when you damn well feel like it, and that you don't want to hear another single word about it from them.
Also, tell your sister, your aunt, or anyone else who thinks it is appropriate to give you a hard time about caring for your extremely sick little baby in the way you instinctively know is best for him, that they can keep their opinions to themselves, and they should know better than to badger the mother of such a sick little child, and to pressure you to stress him with weaning at a time when he has more than enough to deal with as it is.
Absolutely do not force any kind of weaning that your son is not ready for. Constant crying is the last thing a baby needs when dealing with an illness. It drains him of the energy (and calm) that he needs in order to rest and get better.
Don't make any baby cry it out. There is a better way. You can feel it deep down as a mother that this method isn't right. That feeling of stress that you have when he cries is there for a reason - it is there to get you to your son to comfort and care for him till he is calm again. Your son, in particular, needs to cry as little as possible because he is sick and needs all of the energy reserves he can call upon to get better. Be his advocate and his ally in providing a peaceful environment that promotes a strong immune system.
You can learn more about how to wean him - WHEN YOU AND HE ARE BOTH READY (not when others ignorantly feed you stress about when they arbitrarily decide you may and may not nurse your child) - peacefully and healthfully - by reading the Sears Breastfeeding Book, or going to askdrsears.com, or browsing the La Leche League website, llli.org
Do what you know in your heart is best for your baby. Don't fall prey to the misguided prejudices of people like your sister and aunt, who are just uninformed members of an oversexed society that makes intimate but natural and healthy mothering behaviors like breastfeeding "dirty." Your breasts are not disgusting, and breastfeeding your child is not disgusting. It is absolutely natural, normal (the world over!) appropriate and extremely healthful for children at his age - and twice it! If you were not meant to nurse your son now, if it were unnatural, your milk wouldn't be there now, would it?
Stay strong! Your baby really needs you right now!!
L.