Right... so let me tell you this upfront... he was NOT your last chance!!!
Every since I was little all I ever wanted to be was a mother. I wanted to get married, have children, and live happily every after. I was 18yrs old when I met my first very serious BF - he was so wrong for me in every single way. We were worlds apart in everything, we had absolutely nothing in common, he was unfaithful for the entire 10yrs I was with him, but I had convinced myself that he was my one and only chance. I remember having countless tearful conversations with my mom, even with my boss at the time, that I didn't want to give up on trying to make it work because if we were truly over then I might never meet anyone else who wants me again. No matter how many times I was told that this was ludicrous I just wasn't brave enough to risk it.
Until, at age 28, I had a hunch that he was seeing someone else (this had happened so often before that I could read the signs by now). I called him out on it, told him I knew everything (which in reality was merely a hunch) and he confessed. I kicked him out (this had also happened many times before)... In the back of my mind I know I was thinking it wouldn't be permanent. I was thinking he'll beg for forgiveness and if he grovels enough we can try again... maybe this time will be different.
But before that could happen I went out with a very good friend of mine who was trying to cheer me up. We met up with her fiance and some of his friends that i'd never met before. I was instantly attracted to one of his friends but any time in the past, when there was an attraction between me and any other man, I would ALWAYS turn them down because even though my BF wasn't faithful I didn't want him to have a reason to leave me - I didn't want to upset him because then if he left me, in my eyes, it would have been my fault and I would only have myself to blame when I was old and alone.
But this night, after 10 years of being too scared to let go, and knowing he was probably with another girl, I just let go of all of it... I let go of everything... I was so emotionally drained that on that night I just didn't care anymore and in that moment I decided to risk a life alone to see where it got me - I spent the whole night, that night, with my now DH... and every single day after that... my BF came crawling back like I had anticipated but when I let it go that night I realised that it may have been the best thing I ever did so when he begged for forgiveness I told him I just didn't have anything more to give. BF then proposed. It was his trump card, he knew I wanted that more than anything and he baited me with it but I had got a glimpse into another world, another world where someone else did want me. I had convinced myself for so long that he was my only chance but I was so misguided. I turned his proposal down and I never saw him again.
I have now been married for 12 years this June. My DH is my very best friend, he is everything I could ever have wished for and a million times more. We have 2 of the most beautiful children and I feel eternally blessed every day of my life. During those 10 emotionally draining years, if anyone had told me I would meet the love of my life and have 2 perfectly beautiful children, I wouldn't have believed them.
I wasn't expecting to meet anyone that night, you just never know what's around that corner and I bet that your happily-ever-after is closer than you think. Please don't settle, he absolutely is not your one and only chance. Let him go and embrace those other opportunities that life throws at you.