It's good to exercise your PC muscle, and exercising it doesn't create erection problems, in fact, such exercise will help you maintain this muscle over your lifetime.
I don't know why you have no feeling. In fact, no one can give you the answer to that. If your penis is truly number, and it's not just something you're imagining out of anxiety and worry, then you should see a urologist for an exam immediately.
You don’t mention whether you’re getting morning erections. If you ARE, that’s an indication that there’s no underlying medical condition. If you’re not getting morning erections, that could be a sign that there's a medical reason for your numbness.
If, however, you've simply panicked because your penis didn't behave the way you think it should, you've probably created a self-fulfilling prophesy. In other words, the more you worried, the more your penis wouldn't cooperate. When you become anxious and start to worry, your penis wants no part of it. Erections come and go. This is part of life. You’re HUMAN.
Our society does a terrible disservice to men by raising them to think that their penis has to be 10 inches long, hard as a rock and last all night. It’s no wonder that many men feel insecure about their sexuality. Great sex involves your whole body; in fact, having great, mutually satisfying sex is usually quite the opposite of what you see in those performance-oriented sex videos.
The more you think of sex as being about performance, the more worries you'll have. If you're stressed, you'll probably worry even more. And this can be a vicious circle. For most of us, sex is about fun and pleasure. If you think of it as performance, or a “job,” you’ll set yourself for a stressful experience. Remember: Performance can be the enemy of pleasure and fun.
Men receive so many messages that sex is about “performance” and pleasing a partner, rather than just enjoying the pleasure of it. Everything is goal-oriented—like a football game. The other message that many men receive is that sex is somehow dirty and wrong, unless you’re doing it for reproductive purposes. Sometimes this can creep into our unconscious thoughts and sabotage any pleasure.
The best thing you can do for yourself is relax and stop worrying. You'll find that once you stop worrying about erection, your body will respond automatically once your brain stops getting in the way. Best of luck to you. Dr. J