Wife is in prison and is a drug addict

Hello. First can I please request that you don't use my real name. Thanks in advance.
My wife is in prison and I knew she had a substance misuse problem but what I didn't know is whilst I was working nights, she was selling her body in the red light area to make money to buy more drugs. She had been prosecuted before for it but I had no idea because she did not use our address when charged by the Police and prosecuted in court. This time around it caught up with her and she is now in prison. I have to go for STD and HIV tests because although she has told me she always used condoms, she confessed that she had shared needles with a friend but her friend was clean and trustworthy. I am devastated and I have no idea what to do. I feel stupid and naive and feel like she has ripped my heart out. I don't want to go in to the personal bits but all I can say is that she used the needles in discreet areas on her body so there wasn't any track marks on her arms if that makes sense. But nothing makes sense to me at this moment in time. I don't feel up to visiting her in prison because I am so angry and feel like she has used me as a meal ticket. Thankfully there are no children involved but it doesn't make it any easier. I don't know whether to walk or stand by her. I have joined Sober Recovery and found it through your blogger site and the forums are very helpful and supportive but I need to talk face to face with someone. I have found a support group in my area and I am dreading going to it incase I break down. I am scared of visiting her in prison incase I break down in there and make a fool of myself. Please has anyone on your blogger site been through anything similar? Thanks in advance. Anonymous.