Is this Prostatitis or other problem?

Before 1 year I had night fall which cause hurting or burning pain after that I'm getting urine symptoms. For 1 day I had burning while urine and change in urine flow...I drank lot of water as said and urine burning stopped..but after month again urine burns...which stayed for some day and then goes... I get this symptoms for days and it goes and comes after month... facing form 1 year... Before 4 months I had constipation problem and that time pain above anus and hardness feeling... Now I'm getting burning while starting urine...no burning after urine... But while passing stool urine burns and it fills warm fir around 10-15 minutes after pooping? Stool passes easily no pain no burning...some stool stays in...is Prostatitis causing this? Do I have prostatitis? I'm so scared and stressed? Age 21 I don't get any discharge from penis... Urine report shows acidic urine.