I am sort of - although my struggle is with worrying about myself, rather than worrying about another baby like the one I have. Ds is 9.5 months and has been fantastic. Slept through early, fed well, is weaning pretty easily and is always happy.
I've had terrible pnd, which i don't want to repeat, and I'm petrified that another baby would put me back to square one. Also, similarly to you I'm scared that another baby might not be the same as Jak personality-wise, and that would throw my life completely off-track because I'm only just starting to cope with being a mum to an 'easy' baby!
Furthermore, I had what might even be classed as a traumatic birth, and I seriously do not want that to happen again. I don't trust the NHS, I don't believe for one second that the people who looked after me would do a good job if I was to have another baby, and I am beyond terrified of history repeating itself.
I'm content with Jak, but hubby is very very keen on another baby. I read a lot on here about ladies who are trying to convince their oh that they should start a family - it's the other way round for us. I don't think he understands what is physically involved in carrying/worrying about/delivering/looking after a baby. Not that he doesn't help, just that it's easier for him. I've only just got my weight back down, and if I'm honest I'm enjoying being able to wear all my old clothes. It is not something I want to repeat, and I know that it's much much harder to lose baby weight the second time round.
So in answer to your post, I'm kind of in your situation, but I'm not quite there in that I really don't want to have another baby. It's too much of a risk for me. We're meant to be starting ttc in December/Jan and I'm dreading it. In fact, I refuse to let hubby near me at the mo because he keeps making jokes about getting me pregnant. Not useful!!!
I hope you find a way round your feeling hun x x x
If the other EmilyB reads this, can I have my username back please?