How to stop a nasty incident replaying in my head

So it's in the title really...my husband fainted in our ensuite at 2am Mon morning. I was woken by the thud of him hitting the tiles & found him face down, unresponsive 😧 I've never actually seen him faint before so it wasn't the first thing I thought of. I had 2 sleeping kids & didn't even know he'd got up so it was all quite a nasty shock...thankfully he came round just as I got my phone to call an ambulance. I keep hearing the awful thud then seeing him lying there 😢 I wish it would stop!