if you shield yourself this would be an ideal form of what should be done. pretend you are cased in a shield that is probably very shiny so that no one can drain you're magic so it deflects them just do this for a while also imagine you are safe in you're shield .
Nothing can touch you or drain you're magic.Also imagine you're shield is non stick
so that you're enemies can not latch on to you're shield. Go to my other posts grounding and centering if you want to shield because if you don't ground and center first you will become drained in you're shield from negative energy trapped inside. and you can easily be drained by other people.