What does a burning sensation while and after peeing with discomfort and white puss and blood coming out of your penis mean?

It means that there is an std. It needs the attention of the medical profession. See a doctor or go to a clinic.

It could also be a urinary tract infection. It has many of the same symptoms. (Burning before/after urination, puss, blood out of penis.) Either way, see a doctor and let them treat you after they get a more definitive diagnosis.