Fergal, Augustus, I really feel for you, but the very best thing you can do for yourself is to walk away from this JW guy, physically, mentally, emotionally, any way you can.
Jehovah's Witnesses believe that homosexulaity is totally wrong and belongs to the devil.
They believe that their religion is the only religion and anything else belongs to the devil.
As a Jehovah's Witness, the only way your friend can carry on talking to you is as a potential convert. In other words, he cannot accept you as a Buddhist. He cannot accept you as a gay lover.
But he may talk to you to gain a semblance of friendship and gradually try to convert you to becoming a Jehovah's Witness. In fact, in my experience, and I know a number of men who were actively gay and did become converted by JW men, your friend is actually really fairly likely to try to do this. It might feel to you as though he reciprocates your feelings for him.
He can't. As a JW, he simpolay isn't able to do so.
If you value your Buddhism, and personally I see so much that is good and attractive in Buddhism, the whole approach of loving kindness and more. you cannot gain happiness by pusuing any kind of relationship with this guy. Take him at his word. He's told you that the only possible relationship is as co-workers. That is right.
I am really sorry to give such discouraging information, Augustus, and sorry if it makes you sad. But it is better to walk a way now that to bring heartache on yourself in the future.
I feel sorry for the JW guy too. The Watchtower is no place to be for anyone with gay tendencies.