02 GU 4.8 Auto - leaked now whines and now seems to be slipping

So my fairly recently acquired 02 GU has had a bit off a leak which it turns out may have been more than a bit and from the transmission. She started a whining sort of sound when under power which initially I thought I'd put a hole in my exhaust...

Today it started slipping and is not getting power to the wheels like it did and on a normal road drive today in ttaffic the transmission temp was up near 100 which isn't normal.

Now given that it's Friday evening I'd like to get onto this asap and even if it's just topping up some fluid as a temporary measure until I can the leak fixed etc.

Is there an alternative fluid to the Nissan j matic I can use?
If not where can I source fluid on a Saturday?
Any other suggestions or recommendations welcome....

Based at Greensborough Vic

Cheers

Dave

Theres no quick fix here mate I think the transmission might be ready to die
best bet is to put some oil in it any fuel stop or 4x4 shop will have some
then find a gearbox place and send it to them to fix don't drive it till you top
it up or it may stop

there are alternatives but yet to find one thats as good. the penrite one as a temporary but i wouldn't leave it in there

Crap! Not what I wanted to hear - who sells the genuine stuff?