Why am i earning 14 LP per game and losing 20 LP when my mmr is average and on a 4 game winstreak

you have 252W-250L. After 500 games at pretty much a dead even 50% winrate the system has decided you are at the right ELO. The 4 game winstreak doesnt mean much because you're averaging equal lose streaks

git gud

Your MMR clearly isn't average. Ranking sites like op.gg just give a loose estimate. It's not actual MMR. Only Riot knows that and they do a good job of hiding it with abstractions like promos and shiny metals.

because you mostlikely have a negitive W/L, and you;re still coming back from a losing streak or w,e,