leo468, please realize that I am only an amateur astrologer, not a psychic or detective. I might be mistaken. But I think that your fiance is being deceptive with you about his desire to meet soon and get married. I think that you will find him, however, if you keep inquiring and looking. Hopefully you know how to contact his friends, family, and employer if you have not done so already.
He is symbolized by Mars, in his turned 12th house, which rules secrecy and deception. Mars is weakened by being. in the sign of its detriment. Mars picks up no other essential dignity. It is in mutual reception with Venus (you) so I think he likes you well enough. Venus is also in her detriment, but she's angular and in her own terms, so somehow you're in a stronger position to continue the relationship than he is. Possibly he feels he's just not in a good position to marry, or not ready to marry.
The moon (your emotional stake in the matter) next applies to a sextile with Mars. This is a favourable aspect suggesting that contact will be made, but since the moon is the faster-moving planet, it looks like you will be the one to try to locate him.
If he's gotten "cold feet" about the wedding, it's too bad he couldn't just tell you, and face it like a man. But I don't see any evidence that he's come to physical harm, although you seem to be worried about this. After all, he made a choice to disconnect his phone. A true missing person probably would have disappeared without first taking the step of cutting off his means of contact.
Please let us know what happens. And good luck with this.