OK so i just got some news from my mom/employer that I need to be home from school earlier than expected.

Here's the problem with this, I'm flying from LHR or LGW to MCO on 14-Nov any time or 13-Nov after 1 p.m.

I've looked on ITA and it looks like the flights are going to kick me in the rear price wise. I already had a ticket on AC but they won't allow me to change it.

What should I do?