How do I divorce a deported immigrant?

I was young and naive and scared to be alone. I got married with my then boyfriend. I have not seen this person since 2010, which is the same year the marriage occurred and he was deported. It has been 7 years that we have been separated. Recently, he had found me on Facebook and when I requested for a divorce, he said no unless I give him money basically wanting to extort me. I feel like I do not have much options which is why I have waited so long. I am ashamed of my situation because no one in my family knows that I became married. I was embarrassed at the time because I was young (barely 19) and didn't want my family's judgement. I live with my mistakes every day. It is like a big weight sitting on my shoulders holding my life back and I cannot enjoy my life because of this. I have moved on, and I have a 3-year old with my current boyfriend. He is the only one who knows of my mistake and I just want to move on from this chapter. Right now, I do not know anyone he once knew in the US and do not know where he resides currently. But I do know the city (town) and state he is from.