<human>: Can you give me the gist of the text in a nutshell?

My best friend [16M] and I [21M] have been fighting A LOT recently.  

We've been best friends for about a year and a half now and as of late, things have been really rocky.  Our relationship is odd... I've never experienced anything like it before.  We're really close.  We basically know everything about each other and normally spend time every single day together.  I'm in college and he's in high school and he'll come over everyday and stay at my house until 11 when I take him home.  

The weird part is, we almost treat each other like we're in a romantic relationship.  There's no sex or intimacy or anything like that, but everything else is the same.  We text each other constantly (when we're not fighting) we both get jealous when the other hangs out with someone else or hangs out with other friends.  When we get in a fight, usually over stupid, petty shit, one of us wants to end the friendship immediately, then we'll make up like a week later and talk about how much we missed each other.  

It's really weird.  It's like having a girlfriend, except he's a guy.  I've never experienced this with any of my friends.  He actually has a girlfriend (I'm single) and he even say he treats me and her the same way minus the sex.

Recently, things have been gong really bad.  The fights are way more common and now we go days without talking to each other.  It's been happening very frequently.  I don't know what to do.  

Any advice on keeping a relationship like this healthy and strong?  He's the best friend I've ever had.  And has anyone ever experienced anything like this?  Any help would be appreciated.
<bot>: My 21 year old self and 16 year old best friend fight like we're married. Is this normal? How do I fix it?