Thank you all for the further replies and kind support you offer

@Sharon, I have though about trying to dilate a little myself, but I am rather scared to. Not sure if that makes sense.
I did try a little with my finger, that was possible to around 2", but it didn't feel good to do so, and I am paranoid about damaging something. Having nails doesn't help here!
I also tense up 'down there' when I try, which makes things doubly difficult.
Maybe my pubic bone is particularly poorly arranged to allow dilation? I dunno.
Actually reading through some other posts on this site, I came across one where someone's neovagina would almost close up when they got aroused. Something to do with leftover erectile tissue or somesuch. That post really struck a chord with me, as I think I have that problem too.
<sigh>
I know of no post-op specialists in the UK, indeed posting on a forum such as this was my tentative way of trying to find out such info.
You mention seeking surgery and possibly going back to Thailand again, but as I posted, my circumstances now make that very difficult. My fear of losing the life and family I have now, outweighs my need to 'sort out' my anatomical issues. Thinking about that just makes me bitter.
How would I know if my surgery was done correctly? Like I said, Mr. Thomas examined me 5 months post-op and could find nothing wrong.
I can't eat yoghurt, as I have a dairy intolerance. Actually, I'm pretty healthy, I exercise, don't drink or smoke or take drugs. I only drink water or juices. Yes really! My BMI is within the ideal weight-for-height range. Not sure what else I can do, health-wise?
@Jenna, I use Canesten thrush cream, when things get sore or swollen 'down there', I put some on, and 75% of the time it clears things up.
My hayfever and high summer levels of histamine can cause painful sensitivity and swelling there too, which I treat with anti-histamines.
My GP and I have run out of things to try, and he's no gender-specialist.
It can also get sore if I walk too far (for more than an hour), and riding a bike is completely out of the question, unless I don't want to sit for the next few days. What a silly compromised life I end up living.
I am conscious that I sound like I'm wallowing in self-pity, I don't mean to.
@Dena, I had never heard of that condition that cis-women can have. My fella's mum is a nurse, so I try not to do anything that would cause her to become suspicious of me. I'm pretty sure that she'd jump to the conclusion that I'm not cis-gendered if I tried to say I was born without a vagina. I mean, she's already dropped enough hints that she wants grandchildren, and we just laugh it off. Ha ha ha

(
What I did do, after the responses I got from this site, was to contact my surgeon in Thailand, for the first time since my op.
Not sure if he'll reply, and if his answer is to go back to Thailand for more surgery, I'm not sure I can do that, for reasons I mentioned earlier.
But at least it's a small step I guess.
Thanks again to you all for your kindness.
V