About solo/duo program logic

I feels like it is very hard for me to continue my old acc every season. Its like I always start like 15wins and 15loses when the season begins. And unluckily when I get into a lose streak, the win rate drops down so fast so that I always meet unsportive people... But when I start to play a new acc and climb from silver to diamond again. Because the initial smurfing advantage, I have a high winrate initially so that It is even easizer for me to climb... I feel that there is something going wrong with the program logic. The que programme should be rewrite to make the two situation equal. Or it is unfair...

Plz ignore some gramma erro...English as a second language XD.