"Visions" occur within the exact same way dreams do, including day dreams. This makes it difficult, sometimes even for the most adept psychic, to know for certain if a vision is a fear or wish surfacing to their conscious mind.
My best advice is to have someone you trust give you a reading. I don't suggest you do it yourself for the same reasons as above. You could simply be reading into your own fears or wishes. Basically, this situation is too close to your heart for you to know what you are seeing is a legitimate possibility.
But regardless! If both of you have feelings for one another and you think it could go as far as marriage, don't let visions or divination stop you from giving it a good effort! If you don't try, you may always be asking yourself "what if?" and that's never a good thing! What if you try to rekindle your relationship? The worst that could happen is nothing! You have nothing to lose.