Hey, I've have had other people come to me and tell how well behaved my children are. I feel like sending them home with them for a couple hours and see if they still feel that way when I retrieve them.
Actually, I was worried about the neighbors hearing me scream in frustration. I sometimes feel like going outside and screaming at the top of my lungs. I have actually screamed at the top of my lungs when they were all fighting and screaming and I was completed frustrated with them. It did shock them into quietness temporarily. My husband has been know to sit and boo hoo with them when they are all crying and fussing and fighting. They all stop an look at him like his is an animal at the zoo. Actually, my husband can control them and make them mind better than I can. That makes me mad!!! I am they one stuck at home all day 24/7 with little relief and I can't get them to mind me but he can walk in the door and say go clean your room and they jump and run and toys start flying. I can tell them till I am blue in the face to go clean their room, I can punish them for not doing it by taking favorite toys hostage, etc. and I can't get them to do anything hardly for me.
I can't wait for school to start. My middle child starts school this year and since he is the instigator of nearly every fight among my children it will be a relief for school to start. Some one told me his picking fights with his older and younger sibling was middle child syndrome. He does not have the privileges of his older brother (5 years older than he) and he is not being babied as much as his sister who is 2 1/2. I don't know, but it is a relief for me when he alone goes on an errand with Dad or goes home with an aunt or a grandparent. My house is so quiet with him gone.
As to your problem, I am probably assuming that a lot of the fights are over toys. All or most of the toys belonged to your oldest originally. He or she has outgrown some of the toys and they have been passed down to the next child. He still remembers that they are his and does not want to give them up. He probably also has toys that a 2 year old should not be playing with (choking hazard or too sophisticated for his age) It really has to do with selfishness. They will overcome some of it as they grow older, but siblings fight regardless. You may try giving them a break from each other occasionally. Send one alone to the grandparents or take one alone on an errand. Just make sure to be fair about. Don't always give the same child the privilege or it will be more cause for fight.
Anyway, you are not a bad mom, we all feel frustrated at times. This is especially true if you are a stay at home mom with no relief. Parenting can be overwhelming at times. If possible, find a babysitter and spend some time with your spouse or go shopping by yourself. Sometimes we just need a break. Of course, this is coming from the mom who gets no break. Both of my parents work, my in-laws health is failing and my husband is systems admin for a law firm as well as tech support for several small business in our area on the side. He also does the sound and small jobs around the church. He does not know how to tell people no when they ask him to do something. I think I am married to a workaholic. He leaves most mornings at 8 and does not return until midnight or later every day of the week except Sunday when we are at church and about half or less of the Saturdays.