Ghosted and blocked

Is this a common trait with adhd? Right now I feel completely shocked/lost/hurt/confused and every other word along with it. 
 

so for some context, a guy I've been happily dating (he has adhd, medicated) for 9 months. All super happy, attentive he was the first to call me his girlfriend, introduce me to his mum etc. one day, I receive a random text from a girl who says I'm with her boyfriend. I didn't respond but instead told him. He washed over it and said he'd explain later and carried on asking/telling me about something else that was bothering. 
 

She then phones, and tells me other things. Then she tells him she's spoken to me. He gets angry, screams at me (I've never been on the receiving end of his anger before). Still doesn't explain anything, just that he is "dealing with this"; and then blocks me on everything. 
 

So now I'm ghosted, blocked and left to assume I am single. I've always put him first (that's my own fault I guess), helped with everything physically, emotionally, financially. And now it feels like I've also been wiped from history as if I was never even there. This has set my depression to rock bottom mode, and I feel just horrific. I knew people ghosted but to end a relationship with no explanation at all just feels beyond cruel. 
 

would appreciate any help or support. If anyone else has experienced it. It's also embarrassing as there's no closure or explanation. I can’t quite understand how you mean something to someone and then you're dead to them. On every platform erased and blocked.