How does matchmaking in normals work ?

I haven't played lol i a couple of months since i didn't had time. Btw im a gold player from previous season. I won 4 games in a row and then chaos unleashed ! 5 games in a row on my team i got feeders/trolls/noobs that right click enemy base xD (i'm kidding but you get the point ) VS platinum,gold players . I am so frustrated with the game right now and i am wondering if someone can help me understand this? How is it possible to end up with worse players against ranked players if you are playing better ?! How is that logical , what matchmaking algorithm is that ?? Pls riot , i don't want to lose interest in the game because of this , and i invested so much in this game through the years . Pls someone tell me a good reason for this ?! Thanks

P.S I am not going to play ranked since i haven't played for a while , if you are asking ... :)