Age challenge and the dynamics of our kids

Has anyone else been secretly enjoying the 10 year challenges on facebook.  I'm not a huge fan of facebook itself, so I don't post much.  I thought I would have a little fun of my own.  Here we are vacationing in Mexico 10 years ago (June 2008) versus family pictures near Christmas this past year (Dec 2018).  I was a mess 10 years ago, still trying to figure out how to be a mother to Bella.  Actively pursuing all these different forms of therapy for her so she could have a chance at developing.  I was exhausting myself and it was having no positive impact on her development.  It took me a few years to realize that Bella was just going to be Bella and I was going to have to adjust to new expectations.  It's still a struggle for me 11 years later.

Now we have added two more kiddos to the mix, it's crazy around here.  I have known we would struggle with raising Bella and keeping up with two other kids, and it has been a struggle.  What I didn't realize.  As in this completely blindsided me.  How much my two younger children fight, bicker, wrestle, whine, and cry about each other.  It drives me crazy.  I have tried so many different things to get them to get along better.  I'm not saying I want them to be best friends, although that would be nice.  I just want the constant noise and stress of them going out of their way to be mean to each other to stop!!!  We tend to all hang out at home more than most families because of our limitations on getting around with Bella.  It makes it all the worse when being home is constant stress.  The additional part of the puzzle is that they always want to play with each other.  It's really hard to keep them apart and to have them do their own thing.  They always end up gravitating towards each other and then within a few minutes fighting erupts.  And here's the thing.  I like my kids individually.  For the most part I actually even enjoy being around them.  You get two of them together and I want to run away screaming and lock them in their rooms for the rest of their lives.  I feel like I'm failing.  So, if anyone has any good advice, I'm all ears.