Technically all of that is just window dressing. LP doesn't matter, Divisions don't matter, League's don't matter, they are all just shiny graphics. It's only there to make the climb more interesting. The only thing that matters is your MMR because that determines the level of opponents.
Hell, you could lose your Promo series 30 times, but if you maintain a decent winrate, like 60%, your MMR will climb and you can potentially skip the promo series and even entire divisions.
You need to think about you performance over a long series of games, like 30 or 40, and try to improve your play during those games. If you do that and just focus on improving your Win/Loss ratio, you will see a much easier climb.
PS: A "personal skill" Ranking system is a really, really bad idea. That is the whole reason that the Elo system was originally created, to eliminate the highly subjective "skill" ranking systems used in Chess and create something that is objective and backed by statistics.