Good luck, Cathy! I'm on my 3rd-chance career and my umpteenth-and-final chance relationship. Both are working out very well indeed!
It's like making pancakes. In my family we always call the first one the Sacrifice to the Pancake Gods, because it's always wrong somehow: undercooked, overcooked, falling apart. But you can't make the 2nd, 3rd, etc good pancakes until you've made the first wrong one, because it's cooking the first one that helps you adjust the pan to the exact right temperature. So you just feed the first one to the dog, or chuck it in the compost, and move on to the next one as quickly as possible.
And I reckon it's the same with life - there are just some things that you have to learn from experience, and the only way to do that is to just get on with it. Learn your lesson and then put it into practice the next time with greater success!