Self care. That's the really important thing here. The one very predictable thing about addiction is that it is a very self centered disease. An addict doesn't necessarily think about the dangers to themselves and certainly not to anybody else. My son is a recovering meth addict. He hasn't shared a whole lot of his experiences with me but what he has indicates that there was little control over anything he did. If it was going to rush those pleasure centers in the brain, he was going to do it. Of course, sex is a great pleasure rush.
At this point, you are getting tested and that's great. You're taking care of you. Talk to your healthcare provider. Find out whether condoms will prevent the transmission of STD's or if abstinence is important......and then do what is best for YOU.
Addicts lie to cover up their own shame. They lie to keep themselves in denial and protect their addiction. I wouldn't suggest anyone leave their health and welfare in the hands of someone who is actively addicted to meth. Period.
Take care of you.
gentle hugs
ke