my 15 y.o. was stolen off my porch and put down, after being told he belonged to me.

i've had him since 8 weeks. yes, he was sick, on the way out. he was eating, purring, ... and i was watching, every day, for the signs. i already had a spot prepared out back, in my pet cemetery, next to his bestie, 110lb dog. and this... do-gooder was walking by and took him off my porch. after asking my next door neighbor who it belonged to! then she went on social to crow about what a great person she was saving a discarded sickly cat. but deleted her stuff after being called out. i had to go across town to pick up a bag of ashes. evidently she went vet shopping. and even tho she was so, so, so sorry, she never met me face to face. this was back in august. but the thing is, i can get over losing yet another companion. however, i can't seem to get over this. she not only robbed me of my boy, she stole the very last moment, where he's asking, where's daddy? i was ready to be there. and that. just fucks me up. i did file a police report, as in my state pets are property. started therapy even. this is part of it. but it keeps coming back, and i can't seem to shake it. i apologize for venting. he was my boy.