New workload??!!

Last week, pop called me and says he had terminated his HR manager and wants me to go in and temp support him for his payroll. After listening to him, i agreed that i would be the best person to step in and also my sis in law who is working there will also give me some faces. And he agreed that is a temp as i will continue to keep my job in HP. I took urgent leave and worked over the weekend to clear march payroll and had assigned tasks out to the team to follow up with HR's on hand tasks. Now pop is trying to cross his bridge, he says he want to terminate the WHOLE TEAM... ask me to support. He will call me everyday, ask me if i'm going into office. This is going to kill me. I agree that we should change new blood otherwise the same situation will happens again, but we need to hire new people first. without hiring, he wants to terminate all... Who to handle the whole HR dept?? i'm did HR before, but that's many years ago... furthermore, i have my job.. i have Janelle to take care.... but he is just a person cant wait. i cant take unpaid leave to support him till he found a someone. now in HP, we are in our peak period preparing for 2H.... Even since i step into his company, i have not been having good night rest... every night i will sleep at 12am and wake up at 2am thinking how should i handle this situation... to finish HP pending job and to read up about HR... i need sleeping pill in order to give myself a good night rest. that's no good... dont know how long i need to stand in this position. p/s: there nothing call white flag, just bite and hold on tight to the rocking boat till the boat reaches it's harbour.