i'm 24 years old, and sometimes i have performance anxiety, and started using Viagra, i split the pill and i use aproximetly 20mg, i know it have efect the first 2-3hours, but the morning after aprox 12h after i used the pill, i still have no problem performing, i know that is cause i'm not nervous at that time, and i can just continue to have sex... i'm i right or?