Are you actually getting any help with your emet? You may find you can improve your situation a whole lot before you even have kids, with the right help (CBT/counselling/meds/hypnotherapy/self-help techniques etc). Is your fiancee supportive of your phobia? I take it she's not emet?

All emet parents have exactly the same anxieties as you do and some how manage to get through it so take heart in that there's loads of us on here and we all have our kid-related freak-outs once in a while but support each other through it...