splitimage, it is no sign of weakness to do what is the right thing for you...endangering yourself by not asking is not right.
Re your brother's refusal to understand? He doesn't have to, and you do not owe him any explanation.
Be firm that it's a problem with you, and you can always say you can't drink because of the meds you are on...and ask him to honor your request.

Jmo, but bottom line for me is this; if my own request would be scoffed at then I would cancel going.
Disappointment is a helluva lot better than dying inside...and that is exactly what would happen if you take up that first drink. You've worked very hard to get where you are--it it worth throwing it away because someone/anyone can't respect your request?
You are not asking them to eat worms, stay up all night, play cowboys and Indians...as a mature woman you are expressing your need for this to be done for you.
Please remember that you are worth it!

in Peace

In Peace