Right Gerry I'm about to go into my standard pelvic floor chat! please stop reading if it's too much detail or generally not helping!
Firstly, you won't have ruined anything by running but you may have made an underlying problem much more noticeable. If you do have a prolapse stop running for now until you've got it sorted, mostly because it'll be uncomfortable and if you have any leaking that won't help it.
A few questions first that your Dr will probably ask, you don't have to answer on here and if you want to but not in public then PM me. Can you feel anything bulging onto the outside when you wipe after peeing? When you say about bladder control is it all the time, random times or on exertion/coughing/sneezing etc? With opening your bowels are you struggling? (Lots of people that do have a bit of a prolapse have to push on the back vaginal wall to help with opening their bowels but this seems to be some massively unspoken thing despite being common). Most importantly, do you do pelvic floor exercises, if so are you sure you're doing them properly, how long do you hold 'up' for and how often are you doing them?
It's not uncommon to get a bit of a pulling down/bulging/everything falling out feeling after having a baby because the vaginal tissues are stretched in a way they never were before and so you get folds of tissue that you can sometimes feel but this isn't necessarily a prolapse. A prolapse is basically a hernia of other organs into the vagina and is caused by the muscles around the vaginal walls being weakened and losing their elasticity. It causes either the rectum at the back, the bladder at the front or the uterus and cervix at the top to bulge down (at this point I usually draw a picture for people but can't really using the emoticons 
)
Around 40% of primary prolapses can be cured (when I say cured it doesn't necessarily get back to completely normal but you'd stop noticing it) by pelvic floor exercises alone within 6 months and most of these are in young people because their tissues are better and easier to get the muscle tone back in. Building up that muscle then pushes back whichever organ is bulging into its proper anatomical position.
Prolapses at the front (known as a cystocoele) cause urinary symptoms because they change the shape of the junction between the bladder and the urethra which means the sphincter has to work harder to keep urine in against abdominal pressure and so leaks occasionally. Prolapses at the back (rectocoeles) do the opposite and make opening your bowels harder because they make the rectum have a sharp u-bend which obviously makes getting anything out more difficult.
If they don't improve with physio alone the next stage is surgery if the prolapse is a certain stage (we use a scoring system that depends on how many cms away from various landmarks the bulging comes to). There's a few different surgical options which I won't go into in detail as that's hopefully a long way off for any of us.
When you see your GP they'll likely do a speculum examination and a digital pelvic exam. If they think there's a prolapse some of them will refer you to physio, some send you away to do pelvic floor exercises and some will refer directly to gynae. If you see gynae they'll examine you again, score you and then usually send you away for 4 months of physio and see you back in 6 months time.
And so here comes the end of today's gynae rant. I'm definitely better at this than the other chatter. Can I just do gynae fact of the day from now on instead of any other posts?