LP Gains

LP gains in Diamond seem to be absurdly low, like I'm only gaining 15 LP per win, no more no less. I was playing my first 3 games in Diamond last night, won all of them and ended of with 45 LP, lost some games and now I'm pretty much stuck since I'm gaining 15 LP and losing 18. I don't think I'm playing poorly at all and I heard that LP gains in Diamond were nerfed but is this happening to anyone else in Diamond?