1st no your not allowed to, if you do, then its not BOWLING any more, it would be CHUCKING, PITCHING etc etc.
2nd i dont know what can help you, but suggestion keep on practicing or be a batsman or only play the one you like more cricket or baseball
one other thing, in my club there is this dude, who plays baseball was having hard time batting, similar problem. cuz not used to it. when he bats in cricket games, he would have trouble, looks awkward when he stands to bat. but he was still a pretty good hitter. but he got over it. and he is all good now, and still a hard hitter!