When I was manic back in august I was SUPER irritable. I was the exact same way with my son, who was only 2 1/2 at the time. I felt awful. Klonopin helped though. So did Benadryl when I ran out of kpin and the doc refused to prescribe any more.
Irritability is horrible and it's my worst symptom, but you can probably make it till Monday. Just take the Ativan. Take more than usual if you have to, but be careful because that's why my pdoc wouldn't prescribe it again.
Try to do some relaxation, or at least take deep breaths often. Take a few minutes to yourself every hour so you can regroup. I started out having a bad day today and really didn't want to get into another fight with my husband so I went out on the porch every so often and just took some deep breaths in the sunlight. It helped. I wasn't super nice but I didn't get in a fight.