How to deal with conflicting events? [kinda long]?

I have two conflicting events schudueled for the same day. A church member asked me to write, act in, and direct a play for our youth group and aims for it to be done the same day as a group that I am in is confirmed to perform [and it'll be my first performance if I go]. I orginally told the church member I would be joining the group and would like to have been at our first performance for the newer members before I knew a confirmed date. Now both the dates for the play and the performance are on the same day and I'm having a hard time choosing which one to go to. I don't wanna let anyone down by not attending an event.

I tried to ask the church member, and the leader of the group did as well, if we could do it the week after or in the beginning of the summer because 1. Parts have yet to be given out and she wants the play done in exactly a month from today. 2. Both churchs [the group that I am performing with is also church-affilated] are going on a big trip the weekend before so things will be rather hetic. 3. The leader of the group with the performance had agreed to support but she cannot if she has to be at the performance.

I have texted the youth-group leader twice this weekend to talk about when we wanted to confirm the play date and see for one last time if she would be willing to change the date; she has yet to respond. Getting a whole play done and performed in a month is a bit much especially with so many big things going on already in next month.

I kind of want to go to my performance if the group leader is willing to because it'll be my first performance and also I think it'd be very unfair to ask a person to write, act in, and direct a play when they already beforehand told you that they would like to be at their first performance and you gave them the "okay" and then to go ahead with the production without them.

What would you do in this situation?