Well, a gift is supposed to be something the recipient will prize and cherish. It sounds like you did right by him. You were thoughtful, generous, organized and went above and beyond, imo.
The fact that he refuses to buy anything for you tells me that he does not appreciate you, doesn't care about what you like or cherish and is a selfish asshat on top of it. Frankly I think his behaviour is far more offensive than a gold cross ought to be to him. You are his WIFE. He promised to love, honour and cherish you, and he pulls a stupid stunt like this?? Tell me, do you feel loved, honoured and cherished??
No wonder you had doubts about making it to your anniversary. Your mistake wasn't buying yourself a gold cross. Your mistake was marrying a JW.
I'd tell him that a divorce is going to be far more expensive than a gold cross. I'd take the watch back too. He doesn't deserve it.