Dear Nancy, my thoughts and prayers are with you. I don't and can't claim to understand exactly what you've gone through but it must have been so horribly traumatic. The only advice I can offer (from my small experience) is to talk to someone. Be it your friends, family, therapist etc. as sharing these emotions can be freeing and relieving. Write them down if you prefer, but do get help soon.

Don't beat yourself - likely no one could have foreseen it. Often suicidal people can project such normalcy and happiness to others (I should know, been there). It may be hard to see this now but surely he wanted you to live life to the fullest and happiest. My heart goes out to you and once again, please take care in this difficult time.