LOSE MORE LP THAN I GAIN?

so well, when i win games i gain around 18-20 lp, but when i lose, i lose 21-26 lp, i read around this and it says that it depends on your MMR, but my MMR is 1411 and the average for silver 2 is 1368, so it says that i have MMR as a silver 1 but i still lose more LP?! i get so tilted on this pls can someone explain?