HELP! INTRUSIVE THOUGHTS!

Hey guys so tonight I'm having A LOT of intrusive thoughts. But really really ugly. I keep repeating myself that this doesn't matter, that they don't have power over me, that don't matter what they say I'm not that person anymore and they don't define my reality, but they keep coming and they keep coming. I'm starting to feel a lot and I mean A LOT of anxiety and I'm genuinely scared. Any advice? Please I really need help.