Battery/electrical issue

Hi, you guys were right last time I asked a question so I'm hoping to get some more insight to my vehicle. I turned it off for a minute after I had been driving it and it wouldn't start and battery was dragging. Never had a problem with it before. Jumped it and was okay but wouldn't start next time. I put battery from my other car in it but was little too big so I laid on its side. Worked couple days then was drained again. Looked like water poured out. Put more in it and jumped it and started. Didn't put back on side but left standing and just latched hood didn't shut all the way. That night was drained again and when I opened hood it was smoking maybe from the cables. Since then nothing has made it start. Not jumping or a new battery or anything. Before all this a few times when I turned vehicle off something stayed on running, maybe starter, until I unhooked battery and had burning smell so I'm wondering if could be starter. When I try to start it does nothing. No clicking. All lights work.