I think you really need to talk to her about this and share your feelings. You also need to get crystal clear about health risks AND what she has been doing.
Her lies and deceit over this are defensive on her part and a sure barrier to any kind of forward progress in your M, emotionally and/or physically.
You are a human being. You deserve to be informed and understand what is going on so that you can make your own choices. She is robbing you of your autonomy. You do not need to accept this treatment. She will respect you more if you do not. And, more importantly, you will respect yourself more I expect.
I'm so sorry this has happened. I can't say I'm at all surprised. And yes, even if she used a condom everytime, she needs to be tested for STDs. Condoms do not protect against herpes which is transmitted via dermis not covered. And, they do not protect 100% against other STDs and AIDs. If she had unprotected sex, she will almost certainly lie about it. This probably has a lot to do with her panic attacks.
You both need to quit running away from the truth and deal with it, IMPO.
Take care and hang in there. All that has changed is that you received confirmation about something you didn't know.
Also, to repeat, no matter how sincere and heartfelt her confessions are right now, you CANNOT TRUST her to tell you the truth about the sex. People lie about these things. The whole truth might not come out for a year, or never.
You owe it to yourself and S not to risk your health.
