15th month old - discpline

My toddler has been easy to handle so far but is beginning to act out. He gets angry by kicking/shouting and even to an extent of hitting me or the objects near him if things dont go his way. He doesn't have siblings and rarely socialise with other children his age besides his cousins who he meets once in 2 weeks or just his friends in toddler class. Both my husband and me are concerned with his escalating "anger issues". We have tried speaking to him nicely, sternly,raising our voices at him and even hit the bottom of his feet with 2 fingers but he will react by crying or ignore us. He willl then repeat the behaviour again. It breaks our heart to keep scolding him but we really want to nip this bad behaviour in the bud so he wouldnt grow up spoilt or feels that tantrums are tolerable. Help please