Hi K.,
First, let me say don't listen to those who say your baby should be sleeping through the night...every baby is different, and while it may be typical for some babies this age to "sleep through the night", that just means sleeping for four continuous hours a night. With my experience the breastfeeding tends to make the babies wake at night. My two-year-old kept me up every three hours for the whole first year of his life; he wanted boobies, boobies, boobies. I tried warm baths after the nightly meal, to no avail; when he woke, I tried giving him warm water, warm water with a (very)little Karo Syrup, Ferberizing, cuddling, rocking...nothing worked except boobies. I weaned him right at twelve months, and lo-and-behold he started sleeping nine hours a night. My younger son is eight months and he still wakes up every four hours or so to nurse. At this point I just give in, because I know eventually I will be the one who is worse for the wear if I try to get him to sleep without nursing him.
Now, at 2 1/2, my older son still sometimes gets up once or twice at night, and I frequently find him on the sofa in the morning . My (step)daughter used to wake at night until she was over four the same way--except we would find her face down with her butt in the air on the armchair. Then she started with the bedwetting...so you see, it never really ends. You will be sleepless for at the next several years, or at least until you get some quality earplugs.
Good luck,
M.