It's grief, focusing on your deceased fiancee(sorry) leaves your mind to wander and you might be hallucinating. It's normal but you should probly try to get your mind off of him, don't forget about him just let your mind feel some peace even if it's unwanted.
that is amazing about the third eye, just remember not all visions can be good; even pleasant visions can become terrible nightmares...good luck to you in your time of grieving.
its normal to miss him, but do you think he would have wanted you to make u feel this kind of pain? we all loose someone we love at some point, but just for them, celebrate their existance with good memories of them