how am I already feeling this way??

Ladies, I try not to complain. I'm little more than 24 weeks with our third, our oldest just shy of 4 years old. I'm doing my best, but this pregnancy has been the hardest, by far. I'm already incredibly uncomfortable, my belly feels huge and sore, my hips hurt so much that it's hard to walk sometimes. I have cramp-like feelings all the time (but no dilating, thank goodness!), and just don't feel well in general most days. I'm exhausted, and I'm ready to be done. This is so unlike my other 2 pregnancies! I LOVED being pregnant. I was sad when I wasn't pregnant anymore (but so thankful to finally meet my baby!). I try to put on a happy face in front of everyone, but deep down, I'm ready for this one to be over. Is there anyone else feeling this way? Or anyone willing to encourage someone feeling helpless and tired?