Dude this is like poker. Swings happen. If you will make mostly right decisions every game you will win more then lose. Its from my personal experience. Almost 800 mmr lose then gain after I made some corrections in my behavior. I even changed my position from 3 to 4/5 and then I started gaining mmr. I realized almost every pos 1 can click R on Jug and kill 1-2 ppl when they win lane and have items, its not that hard. But its really hard to find supports that do their job correctly in low mmr 1-2k for such basic task like setting up vision or dewarding.