I am very sorry for both of your losses. I also lost my best friend to suicide in 2001 and it hasn't gotten any easier. I miss her just as much today as I did right after she took her own life. There are times I am so mad at her for doing this. How could she do this and leave me here alone without a friend? I am not as mad at her now because I can see how a person can get that low and not know what direction to turn, I have been there.
Something that has helped me some is to write her a letter telling her how I felt. It may help or may not but it may be worth a try.