waiting for the appeal of RC, can I leave the UK?

[amaro]

Hi everyone! Urgent, pls help !!!!
I want someone give some advice to my case.
I got married with husband who is a Portugal after we have met for 6 months when I came to the UK using the Tier 4 visa for study. After married for a year, I need to renew my visa as it would be expired for a few months later. At that moment, I seek advice from the lawyer whether extend my Tier 4 visa or apply for residence card if I eligible for the requirement. After seeking advice from the lawyer, I decided to apply for RC and employed that lawyer for this application. Four months later, I and my husband were invited to have an interview. I found that the interpreter was so unskillful to present my answer. After 2 weeks, we received the refusal letter and stated that the reason for refuse as 'marriage of convenience'. Now, I was pending the appeal. However, my mother is getting serious illness, I want to go back home to see her as soon as possible. The HO has hold my passport and the statement wrote on the letter I can get back my passport if I left the UK voluntary and show the flight ticket for them. My lawyer said to me that if I leave, that means I withdraw the appeal and also represent that I agree that we are 'marriage of convenience'. Also the lawyer said that I have no right to re-entry the UK after I left and in the airport, the HO will hold an interview for me and need me to sign document before I leave.
Can someone have the same case like me?
** I have the query about the knowledge of my lawyer, as one of the reason which the HO reject my application as they said that we don't have joint venture and bank account, but the lawyer said that it is not necessary. He emphasized that many application also success without any of these documents.