How hard is it to climb from gold to plat?

long story short, started in bronze 5 this season and climbed to gold 3, immediately after losing a few 4v5's i noticed it became ridiculously harder to climb back, even taking breaks constantly. i droped from gold 3 promos to gold 5 zero lp in 3 days, went from a HUGE win streak that took me from silver 4 to gold in 4 days then on a huge loss streak, just makes no sense, so i figured, ok im bad let's grind the game and get back there. BUT FUCK ive been stuck specifically in gold 5 for like 3 months now, every 2 matches i win i lose the next 2, every win streaks turns in to a loss streak right after, like repeatedly, i think ive played something like 200 ranked games in gold 5 specifically, i can't climb this tier for the life of me. It seems like every match is so unbalanced, either for my side or enemy. Am i just mentally challenged? seriously i feel like i'm not getting any where since i got gold, i had much better games in silver, low gold feels worse then bronze some times. How hard is it to climb from gold to plat? i have heard that i should just start a new account because i have to many games in now, so my mmr is fucked, is this true? i don't feel like i deserve a high rating, i just want to know how to get there or what i need to do, i just want out of gold 5 lol, if i got gold 4 id be happy knowing that elo hell is a myth for a fact, and that the problem was me all along.