trying times for a toddler...

Brennen turns 18 months on the 19th.. He has started what i believe to be the TERRIBLE TWOS.. For those of you that dont know how he acted before this.. He was VERY laid back.. He was a great baby and has been a great toddler up until now.. It was like a switch was flipped about a week ago... He is throwing himself on the floor , trying to climb out of the buggys and screaming for no reason... So i am at a loss of what to do with this since this is my first child and he has never acted like this before... My family and husband say he just hates shopping or he just wants to walk.. We have tried both and he still does them at home or when we let him walk in stores...We have also been broken from the passy for about 3 weeks now(all but naptime) so this might have something to do with all of this...

We have also started the potty training.. Well were trying.. bought a potty from aafes(waiting for it to be delivered) and no pull ups yet... I put him on the potty about every 2 to 3 hours and some times he goes.. He has been doing great.. I would only have to change him about 2 times a day.. but last thursday he started showing no intrest... I am sure this is normal form time to time but he started not wanting to go when the fits started.. So i am wondering if they have anything to do with each other... Were still trying.. Im hoping he will want to start doing it again soon since he was going almost every time i took him....

So if anyone has any advice please fill free to give it.. It is always welcome :)