K.,
I feel your pain! My second has been much needier than I exected her to be. He is expressing his need for you in the only way he has, by fussing and crying. He may be in pain - getting sick or teething. He may be in the beginning stages of separation anxiety. Something in your lives may be stressing him out. He may be getting ready to learn a new skill like crawling, and it is making him anxious. Whatever it is, remember that what he is expressing is a need for you. My very favorite parenting quote is "A need met will go away." By contrast, if you don't meet his needs, they just get more intense. So go ahead and pick him up. Reassure him that you are there and you want to help him. You won't spoil him by picking him up and carrying him. You will teach him that he can trust you to meet his needs. Studies have shown that babies who are responed to quickly and consistently have a better bond with their mothers and generally have better relationships as they grow into adults. Babies who are ignored learn to stop expressing their needs. They are basically taught that no one is going to answer. How sad.
Get a carrier; it will make your life much easier! With a six month old, I would go straight to a back carrier that has two shoulder straps. A one-shoulder carrier, or one that puts him in the front is not good for your back once baby is around 20lb. An Ergo is a great choice. A wrap and a mei tai are also very comfortable options that may not cost you as much. If you can carry him, I think you will be pleasantly surprised at how much more content he is, and you will still be able to get things done.
I promise this phase will pass. Your son will become independent much sooner than you expect, and it will happen better if you don't try to push him into it! Natural independence comes from feeling secure that you have a safe place to run back to if you need it. Forced independence comes from feeling like you may as well look "out there" because you surely aren't getting your needs met from your family. So all that to say... enjoy his babyhood. While he is a baby, treat him like one. Pick him up. Cuddle him. Rock him. Give him lots of kisses and hugs. There is plenty of time to treat him like "a big boy" when he becomes a big boy. It will happen sooner than you ever imagine!
Best of luck,
S.