Thank you for writing about this difficult topic. I'm no expert but Chris Alar (a priest who lost a grandmother this way years earlier) notes that God transcends time we can pray now for people from our past (it's never to late for God to reach them) so there is always hope because God can always go back to any point in time to help get them to Him.

I've also heard priests say (again, because God transcends time) that there are split second moments where we can think "Why did I do that?" and still be reached. Keep praying and never lose hope. https://www.suicideandhope.com