dogs been acting extremly frightened

yesterday morning one of my dogs which is a beagle,german shepard, keeshaund mix,(male) was outside with the other two dogs which 1 is a full bred alaskan malamute(male) and the other is a black lab(female). the black lab for some unknown reason became upset with the mix an started attacking him, not so much to shed blood or anything but i think it was more of a dominating attack to basically try an show whose boss i guess, but not sure. i didnt actually witness this but was told about it. now for some reason the mix is acting extremly frightened towards everyone and everything, including me. for some reason when i come close to him just to pet him he whines as if he thinks im going to hurt him. id kept him in my room for the day to let things cool off between the dogs but when i went to let him out of the room it was as if he didnt want to come out an avoided coming out. also when i sort of massage the area the lab was nibbling at, his muscles tense an twitch. im wondering if this is something where im going to have to seperate the dogs permenantly or some other unknown thing, or if he has some internal problem. if someone could PLEASE give me any feedback towards this it would be very much appreciated and thank you very much.

Are your dogs fixed? If the female has become aggressive toward the one male it may be a heat related issue. You may want to separate the dogs until the normal heat cycle is over with.
Even if your dogs are fixed, there may be an issue with this. The dogs still have urges but not as much as before being fixed. I might take the dog's actions as a slight jealousy issue.
If after a short separation period, the dogs are still aggressive toward each other, I would stay with them when they are all together. This may sound mean to some, but I would allow them to fight to the point of one allowing dominance. If it gets too aggressive or uncontrollable you may have to step in and assert your "Alpha" dominance.
The dogs may be able to sort this issue amongst themselves. They live in packs so they will have pack behaviors. You may have to allow them this but monitor closely the situation. Obediance training may be called for. Good luck!