What Causes Loss Of Libido Along With Numbness In Penis?

Dear Dr. I am 36 years old married from last 9 yrs. I have one kid 7 yrs old and we are planning for another kid. Lately from last six months or year I have seen sudden drop in my sexual desire and I feel numbness in my penis when erect. I am having unprotected sex from last 2 months without success. I want suggestion for getting back my normal sexual performance and hence get success in conceiving.