Hidden mmr deterioration?

Probably not the easiest question to answer but how does hidden mmr deteriorate? Obviously losing is the main thing. But I was wondering if K/D played a roll or if hidden mmr deteriorated after just not playing after a while?

This season has been rough. I’m on Xbox and I already know that Cronus and Xim are here to stay. Last season I did fairly well and got up to emerald 4 which is the highest I’ve placed. I’m not a phenomenal player by any means, I had a 1.05 kd last season and similar win/loss. Now I’m struggling to even get a kill some games. I definitely think I’ve been bumped up a skill bracket. I’ve been getting slammed this season, seeing a bunch of diamonds and even some people who hit champ. I know the visible rank doesn’t mean a whole lot, but I ain’t that good lol