I want to write how sorry I am for your loss of your brother. I don't know of anyone who died from a violent crime like your brother, how tragic, but I do know there are organizations for Parents Of Murdered Children, you might type that into Google, and see if there are any chapters in your town or nearby that you could attend those meetings. You might also try going to a grief counseling group at a church or hospital in your town, but I think being with other people who have gone through the horror and sadness you and your family are going through could comfort you a lot.
I can imagine how scared and anxious you feel, my father was mugged when I was 15 and he woke up in Bellevue Hospital, when I saw his huge brusied eye and the blood on his face it was terrible I too felt scared and anxious.
Try to just think of your brother as being in Heaven or paradise and that he is where no crimes nor anything bad will ever happen again, also know that he knows you love him dearly, he's just on a different plane so you can not see him in person, but you can see him in your heart. It is so sad when people we love so deeply suffer and die, but some people believe, as awful as it sounds we have a predestiny with our deaths, we all must die and die in certain ways, I have no idea why anyone has to be the victim of a cruel fatal crime, or a vicious fatal disease, or die in a terrible accident, but it just happens. But I heard a rabbi and priest talking once about losing a loved one and they asked, Would you rather had never known your loved one and they lived on, or do you cherish the the time you knew and loved them, even though they had to leave this earth?" and of course we are all grateful we knew our beloved departed loved ones, we just grieve their moving into a new reality and leaving us here, but we rejoice in their kindnessm goodness and all those wonderful memories we have of them.
I hope you can find a support group for people who have lost loved ones to a violent act, I think that kind of death is very different that losing a person to disease or old age or accidents, it sounds so sad. But remember as long as you think of and remember your brother he is not really gone. Love like that never dies.

I do think you need actual help. My husband died very suddenly, though not in the violent way your brother did. I had a therapist for grief who came to see me weekly. I was having terrible flashbacks and she talked me slowly through everything and the flashbacks tailed off. You may not have seen the actual event but the trauma must be enormous, post traumatic shock, most definitely, please do get help, you can get through this I promise you, but you need help to do this. Will you get help?
loads of hugs to you...Cathrynn X

There is no right or wrong way to deal with this. In your case, with such a horrific thing, it may takes months to just get past the initial shock. If you feel you need professional help with this, certainly make some calls. You need a good support system too, in family, friends, or people who are here. Only time allows you to go through this and heal. Huggs,Rainbowmama

I just read your post and my son Sean also died 7/14 so I understand your grief. There are many ways you can help the panic attacks. You might want to see a good doctor as there are many medications that can help you through this. Of course, there are also many groups you can go to. I wish you well, understand it is very difficult for all of us....Sheila

yes, I was put on Lexepro and it helps with depression AND the anxiety and panic that goes with it...I am still on it and found it has helped me cope - it doesnt stop the feelings, though, just helps copes, found I could at least function..