Regarding past life regression Dr. Brian Weiss has shared some case studies you might like to read 'many life many masters'. Although past life regression is an application of hypnosis but it seems that your question is about the attraction you feel about the woman you mentioned. So just let yourself think what is stopping you to express yourself from 12 years. Now, whether it is a past life relationship or not. You can always choose to live in the present moment scenario and work out what you can do today. As they say, you can not drive by looking in to back mirror. If I would be in your shoes what I will do is to analyze the current situation and make a work plan to achieve what is desired. Move forward because no one can live in the past just knowing about past won't be worth delaying what you can achieve today to tomorrow.

There are therapists and faith healers who may Rs. 25000 - Rs. 100000, to tell you were born as a prince and she a princess and both died to to unfortunate circumstances. Or some other fantastic stories. They cash your beliefs, thoughts and fantasies. Yes you may feel good and try to make amends in this life or future thereby complicating your existing life. But there is no evidence base, or logic to believe in that stories. No psychiatrist is taught about 'past life regression therapy' in their training curriculum. If someone is offering then, its your call. Always take an informed decision based on existing knowledge.