Hello,
The numbness can be due to the pressing upon of the nerves by the varicocele.
For the same I suggest you to consult a surgeon and discuss the treatment options with him.
For the pain, you can provide support to the scrotum by wearing an athletic supporter, apply ice to the scrotum, take warm baths if there are signs of inflammation, while lying down, place a rolled towel under your scrotum or try over-the-counter pain relievers, like acetaminophen or ibuprofen.