I travel a lot (in a vehicle) for my work.  I try not to drink a lot during the day (because I never know how hard it will be for me to find a place to urinate).   however, on this day I decided to drink away (water and orange juice).  I had probably frank 1/2 gallon that day.  I had felt the urge to urinate several times but help back because I thought I could hold it.  I did hold it for another hour and then started to feel the urge again.  this time I could wait no longer, pulled over in a grocery store parking lot (about 8 pm), grabbed my empty orange juice bottle and started urinating in it (while sitting down in my car).  only a SMALL AMOUNT of uriine came out before I felt an INTENSE BURNING SENSATION in my penis.  this pain is not pleasant.  I immediately jumped out of my car and started walking around hoping this would alleviate the pain somewhat.  after 20 or 30 seconds, the pain subsided.  while the burning sensation came, my urge to urinate subsided.  when I got back in my car I looked down and noticed I had blood on the crotch area of my sweats (I was wearing sweats, not pants) and on the crotch area of my underwear.  the blood terrified me.  from what I could tell, my urine was blocked almost immediately when I started urinating and then the burning pain came and some blood squired out.  my best guess is maybe 1/2 to 1 tablespoon came out.   I immediately booked my hotel room and went there for the night.  I was very worried what would happen again if I urinated again (would it burn, would blood come out).  some urge to urinate came after an hour.  I did urinate very slowed and 2 things happened.....1) I did feel some burning sensation (but nothing like I had experienced earlier but the urine appeared normal to me.......2)  a very small piece of red tissue came out.  I urinated again (just a very small amount) several times more than night and the same 2 things happened.   the next day I urinated and it appears to be back to normal from what I could tell.   no burning pain, no small red strand of something coming out of my urine.

my questions are:

1) did me trying to HOLD IN urinating have anything to do with this?  I know it isn't good to try  and keep holding it but I have never known what the consequences were.   I know my the time I started urinating, there was MAJOR PRESSURE BUILT UP (I could wait no longer).   and is urinating while sitting down a big NO NO?

1b) if the answer to question one is yes, what exactly caused the bleeding and should I do a follow up visit with a doctor regarding this issue?  

2) if the answer to question 1 is NO, then what did cause this episode (or what is the most likely cause) and how do I prevent it from happening again.