I'm sorry to hear about you father, life takes it's course and theres nothing we can to about it. Seems like you did all you could so hopefully there's no regrets on your part, (pretty common when you lose a loved one ). Definitely the most difficult time in your life when you lose a loved one no matter the age, Only time will heal the pain.
My coworker lost his mom about a month ago, suicide due to mental health issues, he is devastated, and among other things he reminds me everyday to say I love you to your loved ones.