I am at my whits end with my 4 year old son!!!!

Today he is been extreamly in a bad mood. he woke up at 7:15am, got up to pee, and then he dropped a book on his foot, so he screamed and cried. then I woke up my youngest son,fed them breakfast but my youngest was callingo out for daddy, so i took them to see daddy since i had to meet someone who was picking up a toy they bought from me. My 4 year old brings his slinky and was playing with it, then i ordered them a sandwhcih since they both were complaining they were hungry. I asked the guy at the counter if i could have a plastic knife to cut the sandwhich in half and in smaller pieces for the kids. he gives me the knife, and my husband used it as well. then i get some groceries, and some items i needed and head back to my husband. We asked our 4 year old to listen cuz he was acting up and having a melt down. So he threw the plastic kinfe and it hit my husband. So we asked our 4 year old to pick it up and throw it away, he refused and woudn't let go of the slinky. So i told him give me the slinky and i will hold on to it for you until you do what we ask of you. He then picked it up and threw it on another table. At that point i took him in the van and had my husband meet me there with our youngest. All the way to the van my 4 year old is screaming, i get him in the van and buckle him up and was trying to tell him his behavior was not accetable. he was not listening to me and just kept screaming give me my slinky back. My husband comes, puts our youngest in the van and buckles him up. My husband tried talking to our 4 year old and said if he would calm down and say sorry he can have it back. All my son did was scream louder, and unbuckeld himself , taking his shoes off.   We leave after we buckel him back up and i head to drop off the toy. he is still screaming. I get paid for the toy and we head to my sons OT at 10:30. All the way there he is screaming. he unbuckes himself and is running all over the place screaming. I fnally get him insdie and he is screaming more and louder. then i take him to see his OT teacher, he runs out the door and disrupting someones class, i get him in the room, his teacher is holding him and she shuts the door. He screamed there for another min or two and did his work. I went to get him, she said he calmed down and did his work. We leave and he is asking for his slinky and i told him no your behavior you had earlier today was very unaccetable so your not getting it back until daddy comes home and when daddy is ready to give it to you. he screamed all the way home, and we get out of the van. i ask him to go inside and we can talk about his anger. He screamed and said no, i was ready to take him to see our village officer, but when i got there he was not there. So then i tried my neighbor and he didn't answer his door. Finally i get him inside, he sits and screams in the naughty corner, i just let him there until he was ready. He finally calmed down and went to play with his brother. then i called both of them for Lunch and he gets mad cuz he didn't get to play. I explained to him if you wouldn't of been acting like that all morning and since we got home you could of played. NOw i cant wait for nap, since he has been calm he has been giving me nasty attitude.