Since 19(i'm now 32)when i go to pee,many times, flow of urine isn't so strong and with big force,or it fluctuates during urination.i also push to make sure all pee comes out.when other people are around it's worse.i also use to go pee just in case?

You may not have a serious issue like neurological dysfunction. In your case I think the most likely problem is failure to properly relax the pelvic floor muscles. A urologist could evaluate your with urinary bladder dynamic studies and coach you in how to improve pelvic muscle performance, if this is your problem.

With symptoms lasting 13 yrs it is time to have this checked out by a Urologist as you will need a thoro exam and testing which can not be done in this forum for there can be many reasons causing this. Good luck