I concur with Grace, this sounds like typical prostate issues. The burning and trouble with urination specifically. See your doctor and preferably a urologist.
actually this doesn't sound at all like a uti.
at this point go to be seen today or tomorrow and deal with this. the longer you ignore pain and symptoms, the longer it takes to get rid of them . When you are seen , get basic urine testing done as well as they should manually examine your prostate to check for inflammation. Prostatitis can cause symptoms like you have had and can be present in men no matter what your age - it's not just something for old men.
grace
This sounds much less like an STD and much more like a urinary tract infection (UTI) or a water infection.
The symptom of struggling to empty your bladder is a sensation caused by infection or inflammation of the bladder or uethrea. The best course of action for you is to visit a GP, or Urinary doctor and take some urine samples.
I could be something as simple as your diet habits, or something more complictaed - either way, don't lose sleep over it. Your erection problems are more likely a side effect from the worry or concern you are going through.
Hope this helps,
Adam
Probably not. See a Dr and get some resolution.