I'm sorry I can't give more advice, but I know from experience how stressful separations and hams not getting on can be. I know its a nightmare and I know it can be overwhelming, I imagine thats worse when you're unprepared but you'll get through it.
As a short term measure I'd advise removing everything from their cage apart from the substrate and a pile of bedding. Obviously let them keep at least one water bottle (preferably two if you can get a second in a duna - maybe stick one in a toilet roll tube with a hole poked through it or something), and scatter feed.
It'll give absolutely nothing to fight over and might buy you more time, but now blood has been drawn things could get very nasty at any time I'm afraid.
Its up to you if you want to do that and risk keeping them together or find a way of separating them, unfortunately the bathtub will probably be too cold to house a hamster at this time of year