First of all my apologies if this post is in the wrong thread
I am a British Citizen and I am in desperate need of help. Please advise:
My partner and I have been together for over 6 years
I love him more then anything in this world, he is the only family I have.
We lived together for almost 4 years at start, we have always wanted to get married and live together, but I could not marry him initially because I was going through divorce and that took pain staking 4 years to get degree absolute. This left me mentally distressed & suicidal and I have been taking anti depressants for all this period. He was my only support and helped me financially and psychologically though this time. I would not have survived without him.
We moved to separate accommodation not far from each other and lived like that for around or over a year, just to please our parents. This was because his and my parents disapproved our relationship because he is a sunni muslim and I am shia muslim. After a year of advocating my case to my parents I managed to get my mother on my side. When my father found out he threatened to divorce my mother if she supported me and if I went ahead with marring my partner.
I got married to him Nikah (muslim wedding) beginning of 2012 and we are living together since then. My father has threatened to disown me and that he will not let me come back to UK if he finds me in Pakistan.

The problem now is that my partner's visa got expired a while back and he has overstayed. He applied for work permit which got refused and UKBA has retained his passport. He has tried lawyers and have spend a lot of money on fees and it has not helped.
I am faced with the real possibility of losing him forever I have no idea what to do. I am in a panic state all the time and we don't leave the house, we don't see anyone apart from 2 of our very close friends. we are scared and need help.

We can't go back to Pakistan to get married because our parents will not let that happen, and we risk losing each other and our freedom. I don't know what my rights are as a British citizen or as a human for that matter. Please advise!
We tried getting civil registration but without his passport it is not possible. The registrar we went to called the home office to find out about his passport and we got told that his status is now an absconder. I don't want to lose him.

I am scared to death that one day UKBA will come knocking on our door and take him away from me. We have never done anything wrong and have no criminal record.
I don't know what to do? Any advise is appreciated.