Can someone explain 13pt wins and 20pt losses?

How many games do you have to win or what win/loss ratio do you need to offset the abusrdity of 13pt wins and 20pts losses? I'm in Plat V and 2 losses keeps me at this insanely slow climb. 3 wins and 2 losses with this lp value makes it impossible to get out of V - it's just stagnant. Then if I pull off 5 or 6 in a row, I'm up around 70 or 80. 2 losses back to 30. Another 3-2 split still at 30. Then if a 2-2 happens it's negative loss - that hasn't happened yet but this is **only rewarding 4-2 ratio **which seems a bit high for Plat V right? Maybe I'm missing something...