1. 3 RNA NATs only affirms that you were probably never infected. It also shows how scared and worried you are.
2. Such extreme worry is making you look up for HIV information incessantly on the internet, leading to irrational thoughts of undetected virus, delayed sero-conversion, rare strain etc. The reality is, you are probably overanalysing due to either fear or dying, stigma of the disease or guilt of something.
3. Since you are paranoid, you must consider seeking professional help. You did have a risk. However, I can promise you looking at your RNA NAT results, you are only due for a negative at 4 weeks with a duo test.
4. Signal to cut off ratio has nothing to do with any indication, that number can vary due to multiple factors i.e. temperature of your body, time of the day, different testing technology etc. You need to understand that if it's below 1.0, it is negative.
Just get your negative at 28 days with a IV Gen HIV test. It's not normal to keep testing in such pattern, it only reflects that you are in denial, work towards the core of the problem, HIV doesn't seem to be your real concern.