*Mandymoo' I am so sorry to learn of your tragedy. It is such early days,and still very, very raw. People will tell you that time heals -and Yes, it does, but lots and lots of time.
My youngest child died when he was 25 years old, with a brilliant future ahead of him. I was fortunate that at least I had other children. This was 24 years ago,but the grief is still there and the huge gap in our family.
It was two years before I started to come out of that first grief. After five years of meeting up on the anniversary of his death, we stopped that and started to celebrate his life on what would have been his birthday each year.
All our homes have photos of him and the next generation (only one of whom was born when he died), all know about him and refer to him as their Uncle 'G'.
Do not be afraid to talk about David as much as you wish. People sometimes get embarrassed and will try to stop you - tell them you need to talk about what he was and did. Don't be afraid to bore people about this. It can help you.
Sadly, you will find so many people who have an adult child who died, many by their own hands, do not be afraid to share your grief with them.
Do hope you have other family and friends who can be there to support you. I can remember breaking down in anger at one point - and having a total temper tantrum, screaming and throwing things, banging the table - it did help to give me some relief.
Just be kind to yourself. Just remember that he would have wanted you to live and eventually to get back to enjoying your life.