MAJOR Concern/Abnormality

I’m really concerned about my health. My periods used to make me really sick so I tried the pill but I have erythema Nodosum so that’s not an option. I got on the depo shot on July 12th, 2018 and after two weeks of being on it, I got an 82 day period. All of my periods have been brown since then and really irregular. I shouldn’t be having a period at all. I’m currently on my period and it’s red; normal like any other period. I’m really confused and concerned. Any advice?