PollTax, am wearing my Freudian Slippers, so am perfectly qualified to pronounce on your feelings
When we feel such a deep urge for something, be it a baybee or a house move, or new job, or all sorts of stuff, this is because we're craving something on a very deep scale. And just like people drink or overeat or whatever to fill up a 'hole' inside them to avoid looking at and dealing with what they need to address, so too can we feel urges for something that are actually masking what we really want (prolly cos the thing we think we want are more obvious or 'acceptable' or more easily attainable, etc.). Or we could be focussing all our desire on one goal, when we really want several things and all that seems too big, so we lump all our craving into one 'subject' and focus on that. Still with me?
At heart, all strong cravings and desires and wishes point to an innate dissatisfaction deep within the 'soul' (or whatever you want to call it). The question is identifying its true nature. There are so many ways to look at your conflict: is your desire for a 2nd child true? Do you truly want one but it's also masking your desire for other things as well, such as living in Cornwall? Do you want both Cornwall and Baby no. 2? And, more importantly, are you now fixating on Cornwall as something to distract you from the pain and worries of not winning no. 2 yet (which might actually still be your true desire)? As Cass so astutely puts it, the mind can't keep on wanting something so much indefinitely without looking for something else to either distract from the pain or refocus on so at least it feels it's going to get something fulfilled.
I think you probably want both, but feel too selfish to justify getting both to yourself, or maybe getting both seems too big to pull off/you aren't that lucky, etc. You CAN have both, you know. And whilst it'd be annoying adjusting to a new therapist, there are plenty of TCM and alternative peeps in Kernow. Hell, you can't walk around St Ives without falling over crystals and witches and dreamcatchers (bitterness over Ex always making us go on holiday there)!
I have such a massive physical urge for a baybee that I know it's real. But I also know that it's totally amplified by dissatisfaction within me about others things and wishing and desiring other things, like wanting to make changes (or, rather, have someone or something make me change, which pg would do), and wanting to fit in (am a loner and was badly bullied at school, and then have been ill and therefore isolated since I was 21, so really want to be part of the Mum 'club') and also getting older and questioning my identity and wanting a new one, which being someone's mother would create. The issue is so bastard complicated. Or at least it does for over-thinkers like me!
I say dare to dream! Go for both! Perhaps moving to Cornwall and feeling you're 'home' could be the last part of the TTC jigsaw puzzle for you. I do believe strongly that emotions affect our health and making big changes in one area of your life could create big ones on others.
Says me, who's so scared of change that I cried for days over getting slightly-too-short layers in my hair!