L.S.
It's a pretty normal phase that *will* pass....I promise ;o)
Babies are creatures of habit, that's why they thrive on schedules and routine. A new baby always disrupts the routine and, depending on the temperament of the older child, can send daily life into a tailspin. You'll survive.
Patience is key, as is redirection. If you need to focus on the baby for feeding/changing/snuggling, try get your toddler involved in something first - a book, puzzle, blocks, crayons, etc. When your baby naps, devote that time to your toddler - the laundry can wait!
If he's pitching a fit for no reason, ignore it. Tell him you can't understand him until he uses a nice voice. Don't punish him. He's lacking the communication skills to tell you how he feels (upset, left-out, replaced, confused, etc, etc - he's little :)), so he cries.
Hang in there :) It'll get better with time.