Quick question about resistance in 5e

Hi, somewhat new DMing here. I'm using a conversion of the pathfinder witch class, and now, there's this hex that can be taken with the class feature called Unwilling Bond. Basically, if a creature you designate doesn't make their con save=to your spell save DC, for a number of rounds=to your proficiency bonus they are linked to you and take all damage you take. Thing is, you have resistance to all types of damage while this effect is active. My question is, and I know it might sound silly but, if you have resistance to a damage type and you decide to make an attack on yourself with that damage type, can you choose to forgo the resistance? I think this character setup will benefit greatly from the false life spell, and if I can roll a good amount of die, my witch can grab quite a few temporary hp and get in some good free hits. I'd appreciate any feedback anyone can provide I have looked through all my resources to answer this question but I've come up with nothing. So before I say screw it I'm the DM it's happening, if anyone has an actual rule on this please let me know.