Is the istikharah valid and accurate in predicting my future marriage?

I wanted some answers relating to my istikharah. I am an unmarried female. A few years back I have taken khula from my ex-husband. It has been quite a while I have not been receiving any proposals as such. My parents have been worried as well for me. Thus my dad’s friend who is quite a pious aged Imam at our local Masjid suggested my dad that he would do istikharah for me just to check whether I have a second marriage in my life or not. As per his istikharah he saw which he did 2 different times once he saw a huge tree which is beautiful, green and strong from every angle, besides he saw a shadow of a young healthy and attractive man as well. In the second istikharah to reconfirm things he saw a flock of birds (fakhta-chitkabra dove) flying above a female tree. And the most beautiful fakhta amongst them comes and sits on the tree immediately. Thus he concluded from the istikharah that there is a second marriage for me to happen wherein I would get a perfect match. My query to you is that whether this istikharah is valid and authenticated as its asking Allah`s help. But at the same time how can someone know about the future things to happen. So is this true? And how genuine are the answer received from istikharah to take place in future? And what is the interpretation of seeing a fakhta in dream means which as per the imam is a good sign. Please answer all my queries and suggest me a dua as well for marriage. I have already been doing your Ya Lateefo wazifah 1110 times but there is no improvement thus I am confused.