Loss Streak and Raising MMR

So i played my placement matches 3 weeks ago and got placed in Silver 3. My goal was to climb to at least Gold V. I informed myself about the best ways to climb and about MMR so i try to keep my MMR as high as possible. I Climbed to Silver 2 100LP and lost my promos. And then the terrible losing streak began. My MMR was at a peak of 1450, according to OP.GG that is supposed to match the MMR of a silver 1 player. Now i lost about 9 matches with a few wins here and there. I have very few games where i actually play bad or lose my lane. Still, my MMR dropped down to 1320 which is Silver 3 MMR. If i win games i get about 20LP and i lose about 16-18 LP which is kinda unfair in my opinion. A lot of Games someone in the team gets salty and starts throwing or flaming. To be honest this really frustrates me because i feel like i am wasting my time. Especially my last game i got matched with an Irelia who was intentionally feeding from the start (0/9/0) in a 15 min game. In that game i didnt play bad and i wasnt toxic. So i dont understand how i can lose 18LP in a 15 min game that was lost after the first 2 minutes because we were playing a 4v6. I cant figure out how to climb in this situation. I know MMR is really important for quickly climbing, especially in low elo. But if i play well but i just cant win games i dont know why i should even keep playing competitive anymore. So what do i do in this situation ?