I have/had this! I was very lucky to receive cognitive behavioural therapy a few months ago, and what I ended up realising was that over the years in fights with my siblings I'd told them to die and that I hate them and what not, and they've told me the same, and we're still all here! It was hard for me to learn that what I do doesn't affect the world, that words particularly can't do anything. I ended up sorting a lot of my worries like this with CBT, which I'd recommend getting your therapist to do some with you if they're not already, it started with something really small that worried me, and I'd do the thing, sit with the exposure and nothing would happen, then I'd do a scarier thing, and nothing would happen, and now I occasionally tell my relatives (who have been told why I'm saying this of course hehe) hat I wish for them to die, and they haven't! It took a long time and some work but me saying it not doesn't make me worry, and that's a lovely feeling to have and you will have that soon too :)