I need help :(

Y’all I’m up late and in tears typing this bc I’m tired and upset. My toddler is so freakin moody all the time now it seems...the smallest things seem to set him off, such as when he notices one of his toys has the least bit of dog hair on it, for example. The worst part is he throws tantrums in public. I can’t go out without him breaking down right there in the middle of the mall or the grocery store...on the dirty floor. I realize sometimes it’s bc he hadn’t gotten his nap yet and that tantrums are a normal part of development, but I can’t help but wonder if my almost 3-year-old has some kind of psychiatric problem that’s causing his tantrums. I mean when I’ve observed other toddlers in the past and now, most seem very well behaved in public. I feel like I was mislead and wasn’t prepared to handle this. I’m not sure what to do and if what I’m doing is right. Sometimes I feel like I don’t know what I’m doing and I’m just doing this blindly. I’m tired and I feel very defeated...and super guilty. I can’t help but think it’s my fault. I need help. 😢 Any patents out there dealing with this too? Is this normal? What do you do to avoid/alleviate this?? Any insights and/or advice is appreciated! Thanks in advance!