Help please

Can I get a bit of non judgement advice please? Again, please be kind because I’m not doing good today.

I have four kids, 6 and under. They all fight like mad, they literally will have tantrum after tantrum anytime they’re near wachother for the usual kid stuff - “they stole my toy” “they won’t leave me alone” “they hurt me”. This morning has been particularly awful with fighting. I try my best, but I’m a single mum and their dad isn’t involved so some days I’m totally burnt out and today I am. Yesterday they flooded my bathroom and it went though my kitchen ceiling. My 3 year old won’t sleep so I’m sleep deprived. I’m not at my best form right now, doing what I can to get myself better but of course these things will pass I know. But does anyone else’s kids act like this? I think I’m failing them and maybe I’m the reason it’s like this? I try to encourage kind hands, sharing, I even separate them but they seem to enjoy annoying one another. I had my neighbour text me this morning asking if everyone’s ok because all she can hear is screaming shouting and fighting. This has scared me so much because I’m so worried people think I’m this awful mum. I’m trying I really am! It’s suddenly just gotten really bad and I’m trying my best to keep them all happy but it seems I am never good enough 😭 is this normal? Any advice on what I can do to stop these arguments from happening bevsuse the stress it’s causing me makes me feel so unwell! Just to clarify, I love my life and being a mum and I wouldn’t change it. I am just finding this particular moment in time difficult. I know I argued with my siblings loads growing up and now I feel bad for my parents if they felt the way I’m feeling. I’m so embarrassed. Thanks in advance guys x