Hi Chocolatemouse.
I'm sorry to read your story - sounds rather like mine!!!
Have been with DH for almost 10 years and I had finally come around to the idea of not having kids when DS (Now 6 months) popped up extremely unexpectedly!!! I adore him more than life itself but DH is adament that he doesn't want more (to be fair, he also has two DDs who are 10 and 14)
Our DS is just the most amazing, placid, happy, contented baby ever - sleeps well, feeds well, smiles, gurgles, only ever cries when he is hungry / wet / tired and it's STILL changed the dynamics of our relationship amazingly, so please don't blame any aspect of your DS's behaviour - it would have happened no matter what...
I would have another one in an instance, and it does make me sad that DS has no close relatives (we live here to be close to the DDs but they are much older than DS). I would love him to have a sibling...
Your DH has changed his mind once, he can do it again
Also, FWIW, don't be hard on your self about BFing... I mixed fed from day one (on advice!!!!) and DS was 100% FF from around 3months. I did feel bad when my milk dried up, but DS is thriving.
Oh, I am not sure if that's of any help, but I do know where you are coming from.