I get by with a little help from my friends

Today I learned that at times I can rely on other people to help out where I fall short and that it is OK! It was a rough day for me as a mom. I just feel like I kept dropping the ball and my kids were not happy with me. First of all, I love fun things my kids do in school but most especially dress up days and I actually forgot about opposite day at Jude's preschool today. I felt so awful! I love opposite day!!! Luckily my amazing friend Amanda came to my rescue and put him in one of her daughter's skirts when I called her from the train to school. Of course it didn't last long since Jude is so particular about what he wears and he was upset that it was Pennie's and not his. Oh well.
        Later in the day Amanda came to my rescue yet again giving me a kid free hour to go to the fabric store and get supplies for school. I did have one win today though... I went online and printed every competitor coupon I could think of for Joann's and ended up saving $123.01. Take that! Anywho, I felt kind of like a failure for not taking my kids while running an errand. I know moms take their kids everywhere and I still struggle to do anything with my kids in tow. I just start panicking and then struggle to even function. I hate that the fear of stressful situations keeps me from just living my life. It's not even that my kids are that badly behaved in stores it's just the idea of not knowing how they are going to act when I am trying to accomplish something. At home I stop what I'm doing and devote all of my attention to the kids if need be but I can't really do that when we are out and about. This is something I am definitely hoping to master in my new life.
       When I was done and went to pick up the boys I decided that tonight would be a fast food night. No, we don't have them often. I've explained to Carter that it is unhealthy and expensive and should be a treat. So tonight, we treated ourselves. And then the chaos happened. Carter has this habit of overreacting to everything with a very loud, very high pitched scream. I repeatedly tell him this is not an appropriate response to the current situation but then I wonder if I am wrong for telling him how to feel and react. Jude stole Carter's french fries and there it was, the ear piercing, blood curdling scream. I got so frustrated that I immediately sent Carter to his room kicking and screaming and pulled the fries out of Jude's hand. Of course I then had two screaming children to deal with. Oh boy. So I went into Carter's room and he was throwing a huge tantrum and destroying his room. When I walked in he was throwing and kicking Rockem' Sockem' Robots so I told him if he touched it one more time it would go in the garbage. Needless to say Dave questioned why the game was in the recycling when he got home. (We did take it out and put it in storage for the next month at least...) I sat down and talked to Carter about what the appropriate reaction to the situation should have been and made him practice it. Not sure if that was the right or wrong way to handle that but it seemed to help and smoothed things over.
         I just feel like I don't know what to say and how to react to situations appropriately myself. So do I need to practice like I ask Carter to do? Any tips from moms out there that can help me in those melt down moments? I feel like I totally fail in those times of chaos and calamity. My anxiety is heightened in those moments and I don't know what to do. I can't even handle my kids' meltdowns sometimes and it is the worst feeling. Being a mom is hard.