Have you tried googling bladder weakness? There's loads of info out there, one of the causes could be something like an infection. It may not be that your pelvic floor is shot. Can you bounce on a trampoline without wetting yourself, or do star jumps?
agree with girlnextdoor - ask for a physio therapy referral. Pelvic floor exercises should be done daily from when you are a teenager - it's a lot harder to train a weakened pelvic floor then it is to prevent it becoming weak in the first place. But it's not too late to strengthen your pelvic floor, and a physio therapist can help you do this very effectively.
Firstly you need to see your GP. And don't be embarrassed - GP see this sort of thing all this time. It's very common.