Time to re-introduce? Urgent request.. please.

Last night, I took both kitties to the vet. Cassie was an angel.. Monet had to be sedated as he was being a complete demon, completely stressed and angry. While he was still groggy last night, he was growling and hissing.. understandable, he wasn't feeling himself. He attacked and hurt (or startled) Cassie to screaming twice.

I locked Cassie out of the bedroom at bedtime so Monet and I could have time for him to readjust.. and he did around 11pm when he became his snuggly self. I let him sleep against me till around 4 am when I got up to go to the bathroom. Cassie slipped into the bedroom, and Monet growled, hissed and chased her out of the room. I locked her out again.. Monet growled at me for a bit, then calmed down and snuggled with me.

This morning when I let him out of the bedroom for breakfast, he wanted nothing to do with poor Cassie. he went after her, swatted at her, hissed and growled. I had to feed them separately when they always fed side by side as he smacked her away.

I am worried since I will be gone all day for work and the christmas party then tomorrow I'll be gone early morning until sunday night, over night. I really don't want to keep them separated over night since Cassie and Monet liked to share the bed, and share the couch. They also share a favorite littler box. Last time Cassie went to the vet, Monet was growling and hissing, but he sprang back in a few hours. I am sure he's not recognizing her.. was hoping both of them to the vet at the same time would help.

Should I keep them separated today, and watch them tonight? what should I do? I am debating on leaving them both out, but I am scared to come home to a hurt Cassie. Poor girl is clearly upset and confused by this. She keeps trying to go to him, and she waited outside the bedroom door for him while he was recovering last night alone :(

I leave for work in an hour, and I hoping to get a response by then on to separate them or let them be?

EDIT:  I wish I gave more time for people to respond.. I didn't get up earlier and was not expecting Monet to still be a grouch.

I've decided to let them both roam.. Monet's on the bed in the other room.. and Cassie knows how to run and hide. I am hoping for the best.. vibes please when I come home 10 hours from now, all is well.

I'm going to slip home in a few minutes before the office party to make sure there's no fur and blood. I am so apprehensive!

Edit:

Came home, I don't think Monet left his spot on the bed at all this morning. He was fine with me until Cassie came into the room then he started growling and hitting me.

He'd better get over it before I leave tomorrow overnight!

I just put some baby powder on them. Lets hope it works! *sits and waits* Never tried this before, nor heard of it, but I am willing to try anything!

It's either the powder, or da Bird, or combo of both, but Monet did spring back minutes after applying the powder. He was back to his old self.. maybe a little mooshier than usual?

thank you SO much for suggesting the powder! Now I can go away over night and not worry!