You should learn how to shield your self. There are many ways you can shield.
Root shield. This is making a shield out of the roots you make when grounding.
Mirror shield. A type of reflective shield that acts like a mirror. If you don't want it to come through it gets reflected back to the source.
Elemental shield. Shields made up of the elements. Each elements makes a great shield, but also has their oen negatives.
Layers. It's good to have multiple layers of shields. Each layers a different shield for a different purpose.
These are just a few examples. There's quite an extensive layout of various shields and purposes. One could be made to help keep this person from making soe type of connection to you to leech your energy.