Can u answer my question???

Its been a long time i kno but hey been searching for sum answers n sum mental sanitity. Now ive figured alot out sorted alot of shit in my head n placed some who's who and whats wat in my head but one thing i cant figure out one bit is love...yea L O V E, two people meet n spend time wit sum1 n dey or one falls in love wit da ova...What is it that makes people wna giv sum1 150% of themselves n recieve 20% back??? Why is dere a thin line between love and hate??? if they dont love each other then one hates the other even if they wont admitt it...For sum reason ppl spend their whole life lookin for a "soul mate" or sumone to spend their time with??? Ppl base their lives off this n i jus cant seem to understand y?? Granted u cant choose who u love but damn imagine if u culd??? Things wuld b hectic...out of control...chaos to say the least...But for those of you who dont kno there is difference between love and lust....two L words but each is different fromthe other...When sum1 is on da ropes i mean on dey last leg n sum1 helps u even though its all they hav they love u cuz dey wuld rather c u straight n dem struggle den to watch u struggle...make them do out of charcter shit to make sure u straight...ppl can giv u dey last n in return cant even get the time of day wit that person...realitity settles in rit ein front of ur face...u kno it cuz u feel it, as u watch this person smile in ur face and as u hear them lie to u and say they love you...have u ever heard a heart break??? naw cuz its a different kind of pain...a pain that makes u wonder why??? But theres also karma...she plays a huge role in relationships...n doesnt care how u feel...so im askin u can u tell me y is that even though u feel sum1 u love doesnt care bout u as much as u do them y is it so hard to move on to nothing???