I've not been an army wife for many years now but I remember how hard it could be.
Don't hesitate to contact the units welfare support services, that's what it's there for.
Are you friendly with the other wives? Can be good to support each other. One possibility (might seem old fashioned but I think very sensible) is setting up a babysitting circle with them?
How are you able to communicate with him while he's away? When I was still in that position it was very much still paper blueys I'm sure it's much better now. But with such young children paper blueys could provide him with wee drawings from the kids, even little handprints etc I would think it would still be nice for you both too to use them for physical letters (you might feel more comfortable being more personal in these than electronic methods).
Some units also organise events for when the serving personnel are away. That can help with keeping kids occupied.
Mark off a paper calendar - having a clear visual representation of the day's going by can help and once you hit the 2 month mark you know you're half way.
"we don't live on camp unfortunately" you don't have to to use the hive, contact welfare reps etc
Try and focus on the things you can do while he's away, might seem silly but can make things easier eg watching what you want on telly, eating what you like for dinner, spreading out and using the whole bed, going places he's not very keen on...
And the things you DON'T miss about him - again might seem silly but can help eg not dealing with those small but annoying habits we all have, perhaps not having to watch footy or wash cruddy rugby gear or smelly fatigues...
You got this! You sound a sensible sort.
But don't feel bad for having low moments or even being pissed off that he's away and eg not having to deal with a sick kiddy that's normal