Nursing all day

So we've been nursing pretty much every hour since 8 this morning going from 20 minutes to 45 minutes each side in one session and maybe breaking for that long in between each session.  The most recent one was 56 minutes on the right side, then immediately given 2.5oz pumped milk, still crying hysterically so now we are on the left side. Again. This is about to be a formula fed baby because this nursing has been ridiculous today.