Your story prompts me to do something for you. Sildenafin does have bad effects if used indiscriminately which you have observed now.
Numbness and erectile inability of penis can be addressed by herbals under a set protocol if using these with some food instructions and local applications.
The whole idea is to strengthen corpora cavernosa and penile blood vessels. If these fill properly, the erect penis will be as stout as of a young person. Then comes the role of sexual act having broadly four stages in an intercourse cycle viz. Foreplay, Intromission, Orgasm and Resolution. The technical perfection is your own and your partners experience. To sustain the act for long, some herbal aphrodisiacs, known to nourish seven elements including Semen ( as per Ayurveda principles), play an important role.
White pathes can be addressed by local Ayurveda applications made of oils and herbs (to cure skin) which is used before starting the use of aphrodisiacs oil for vessels and cavernous spaces strengthening.
Some herbominerals which are nervine tonics, removes numbness and tones up nerves that additionally helps in maintaining stout penis upon erection.
But this cycle needs at least 7 weeks. Some metabolic, digestive factors may extend duration of treatment.
Hope you understand that herbals and Ayurveda are natural answer to your problem. It is side effects less treatment, safe but slow being naturals and not synthetic and toxic. But its effect sustains and not temporary. User has to show patience to get full benefits.
I feel this will help you.