Here's the thing. You're a good mom. I don't know you, but I'm SURE you're a good mom. You're fishing the internet looking for some help because you think you're yelling too much. That means you're a good mom!
If your child is driving you crazy, it's okay to say so. And it's okay if we lose it here and there. But it would help if you could figure out what the heck is wrong and change that behavior. Then you won't feel so crazy and guilty!!
So you need to look at why your toddler is acting out, and change YOUR approach to nix that behavior. First up is to stop giving in to their demands. They want a cookie, they want a book, they want ice cream, they want to beat the dog with a hammer, and they want to play with the toilet paper. You say "no" and they start screaming. So you go, "Ooooh, okay, you can have one cookie, but I swear, that's it - no more!" And by doing so, you've just given them a reason to continue screaming. They figure out, "Hey...cool! I scream, and I get what I want. Nice!"
Stop giving them everything they want just because they howl. That just trains them to keep howling. It will take several tries and lots of confused crying, but put your foot down and say "no" - and MEAN it. Don't wussy out and give in. If you say no, that's it. End of story. Deal with it. Yes, life stinks when you can't stuff the toilet with rubber duckies, but that's the way it is, little pookey bear.
Will you feel guilty that your child is so upset? Of course you will! But listen up when I tell you that's the main tool in their toolbox. They cry and throw fits to wear you down, or they break out the Mommy guilt zapper. Between the two of those things, darn tootin' they're going to get what they want!
But you and I both know that getting what they want all time does NOT make them happy. It only makes them more demanding. So be the big person and show them some limits and consistency. They absolutely crave it!!! It gives them security and makes them feel safe and in control.
So say 'no' and feel good about it. You know what your child needs more than they do. When the tantrum stops, get on with life. And don't go nuts with the making up part, blubbering on about how sorry you are for making them upset. They're not stupid. They'll sniff out that weakness and latch on like white on rice. So stay firm. Be the rock and support that your child needs. Offer lots of hugs and guidance on behavior you WANT to see, not just "cut it out" "stop" and "no!" Actually guide them on what to say. "Mommy I want this, please." (As opposed to "Nooooo! Gimmie, it's mine!!") If you don't tell them what to say and how to act, they won't know.
Hugs, my friend! You can do it!