Perplexing MMR

Let's start with this. I'm a real bottom rung player... that's clear. However, I want to improve and am struggling to figure out what is going on with my MMR. Rather than list numerous mysteries from the recent past... I'll just go with this simple one. Two games ago, at Bronze IV, 26 LP the system said my MMR was 966 and that was normal for my rank. Then I lost one game and my MMR dropped to 903 (3 LP)... then I had a remake, and my MMR went to 888...? So basically I went from "normal" MMR for my rank (according to Riot), and lost 78 MMR after one loss and a remake... little help?