Thanks for your query.Based on the facts that you have posted it appears that you have enlarged prostate
and now getting pain in penis and loss of libido.
This could be due to prostatitis
Please get your urine routine test and ultrasound
scanning done to done and
consult your Urologist
for re -evaluation of your Prostate problem.
You can take Tomsulosin for a week along with pain killer that you have been taking.