Where could I get Rescue Remedy and how does it work?

Yesterday evening I took Little Boy his bowl of wet food. I showed him the bowl and he slowly came out from under the bed. I picked him up, carried him and the bowl to the bathroom where he again ate outside of the cat carrier. I spent a half hour petting him and brushing him.

I left the room for awhile and when I came back to get ready for bed, he was lounging on the floor. He tensed up but did not run and I did not approach him.

Around 3 a.m. Zam was pitching a fit so I let her in. She immediately went under the bed where all the growling and fighting began. Zam backed off and I fell asleep.

At 4 a.m. I was awoken out of a dead sleep by them fighting and I mean all out, yanking hair, slashing claws. Little Boy was on the floor at the end of my bed. I chased Zam off and Little Boy, although nervous, let me pick him up.

He began purring instantly and I nestled him on my chest and pulled the covers up over him (leaving his face out). Zam curled up at my feet but slowly started stalking forward.

She suddenly pounced, tearing into him with teeth and claws (and my arm and hand which was unfortunately in the same vicinity ) I smacked Zam on the head and she ran off. The minute I started scratching Little Boys head again he started purring all over again.

I'm beginning to feel they will never get along....

He only comes out from under the bed if I coax him, he continuously fights with Zam and wants nothing to do with Kia. He'll growl at her and press himself against the far wall under my bed.

*sighs*