Hi there ~
There is no relationship between your feeling like your body may have gone numb and your body not wanting to have sex. It is quite possible that you are dehydrated during the time of having sex as it can be a very heavy exercise in some instances. I advise you to consult a psychiatrist
to find out if you can benefit from any medications for proper erections. Pain in your testicles if severe needs surgical attention especially so if you also have problems with enlargement or redness
in the area. I hope you find help as soon as you can by consulting the right specialist.
Take care and have a lovely day!