How does MMR and LP gain work now.

I was curious on how any of this works now that the positional rank system is removed. before the reset I was gaining 23 lp and ever since it was changed I have not seen a single game all throughout gold where I've gotten more than 20 lp. I have been consistently winning games in gold 1 ELO, have about a 75% winrate on Kayn and all these games feel like slaughters due to the clear skill difference between me and the average gold player, yet the game seems to want to keep me there with only having a 18 lp gain despite going on several win streaks.

Can anyone shed some light on how this works now, because I've been accused of account sharing multiple times with no evidence to support it what so ever, and frankly I wish I could progress through gold faster so these claims don't turn into an unjust ban.