Dont do it. Dont do anything. I have a friend who took valium to chill for a friend's funeral and ha said he regretted it deeply. He hated not being able to feel anything. He had a much more difficult time integrating and getting past the death because of the valium at the funeral he felt.
Funerals are ALL ABOUT ACKNOWLEDGING REALITY, NOT ESCAPING IT!!! Dont do any "doses" either. A couple snorts of achohol before perhaps but thats it.
You NEED to feel those tough emotions, man... you have them for a reason. They are a sign of your self remodeling and reconstructing.
Worried about crying??? C'mon... the ONE place where it is accepted that its OK even GOOD and a sign of respect for *EVERYONE* to cry is at a funeral, even great big strong manly men. If not there, where??? Tears are your body's way of shedding the pain to the outside so that it does not hurt so much on the inside, where it can fester and be damaging. Need to get rid of that stuff and the only way to do that is to just be a REAL man and go THRU it. So go with the flow.