As someone who lost a dear friend to suicide, I can say that it is something that sticks with you. Don't be afraid to seek professional help and don't hold back from sharing your emotions and pain. You might feel sad, angry and all sorts of other emotions. Something that really helped me was being around other people who were close to this person. We cried together, shared our stories and memories and we held each other close. Just know that it's all going to to be okay.