I am 5'4'' too and I ride a 47cm Felt, but that doesn't mean that the 49 doesn't fit you. I think you should take it to the shop and get fit, if its too big thats not good news since you just bought it, but they can work on your fit at a shop. If it is too big and you want to keep it anyway they can adjust saddle positon and stem lengths and stuff to make it fit the best it can so its a good idea to get a fitting done at a shop.

My road bike felt really wierd at first because I had been riding a mountain bike before but I got used to it. It just takes some time to get used to riding in that position, but I actually like it a lot better than my mountain bike now.