I do feel your best and happiest option would be to get him neutered. It is usually a fuss-free procedure, and he will be out (usually) the same afternoon!
Getting him neutered will be the cheapest, easiest, and less stressful thing you can do right now. Some places do free spay/neuter programs too. There might be one in your area?
Don't feel you are taking away his personality, his 'manhood' or hurting him in any way. I once had a male cat who was suffering terribly. He was crawling round the walls inside the house, growling! And seemed scared to go outside! I was afraid for him, wondered if he was going crazy or was very sick, and in pain. I took him straight away to the vet. The vet suggested neutering him. And would you believe it? Straight away afterwards, he was a calmer, and happy cat. It didn't take a thing away from him. I believe it gave him a new lease of life. He continued to be 'himself' character-wise, but was just much healthier and happier.
The pressure of hormones out of balance can be incredibly stressful for either a dog or a cat sometimes. It sounds like your dog has reached that point.
Something else: Is there somewhere you could take your male to get him completely away from her? Maybe a friend or relatives house? Or have him boarded at your Vet's office for a few days? If you could get him away from her, he will settle down and at least eat a meal.....Just a thought........
NO! There is nothing you can do.......This is part of nature & how it works......It's Vital that you keep them seperated and NOT risk an unwanted pregnancy! This could go on for a couple of weeks!
*Having her Spayed after her heat cycle will solve the problem, forever......
*Having him Neutered will take care of this problem, too. However, it takes awhile for the hormones to adjust, so it wouldn't help you out this round!
There are also, lots of health benefits (Avoidance of certain Cancers) for both of your dogs, by having them altered.....Good luck.....Karla