Left-over energies after a magical working need to be grounded out. Having something to eat and drink can help with this. Or you can touch your hands to the earth and allow that excess energy to flow back into the ground. If there is a lot of left-over energy you might try actually lying on the ground to let it drain away.
Knowing how to ground and center is an important basic tool in working magic. You might want to research this a bit before you do much more in the way of spell workings.