I am sorry that you're feeling such high anxiety about your brother's wedding. Are you seeing a T, to come up with plans on how to work through these intense emotions when they strike? Exercise helped me when panic was a huge part of my world. Perhaps that could help you get through moments when you feel overwhelmed.
Personally, medications haven't helped in a lot of different areas in my life. I've had to go on and find other techniques to pick up the slack. Seeing a psychologist or social worker, occupational therapist, independent living worker, regular exercise, hobbies (puzzles, fishing, crafts, poetry)...those things have helped me feel a little more in control of my life now.
Best wishes to you...