I have a constant dream about someone I used to be with and am still dear friends with from afar bc i married someone else. I have a family. Yet I have constant dreams of this person , in every dream we are either romantically involved or he is helping me through problems. They are very lucid and clear. When I wake the day after I feel so drifted and sad all day. I can never forget the dreams.

It's impossible to say whether or not the person you are dreaming about is your soul mate - in real life now, he might be a completely different person than he is in your dreams - but these dreams are a sign that there is something abou your current marriage that is making you unhappy.