CurlyWurly - so sorry you are feeling like this. I have no advice, but can empathise.
I too had a too-early birth, although luckily without complications apart from five weeks in a lovely hospital being spoilt .. I was trying hard for another and then MC last Easter. I then decided not to try again - it must have been madness! I was so lucky with DD, and yet, not content with one miracle, I was risking another child's health or even life because I wanted more children!
DD is now 2.5 and my two closest friends had babies, exactly when my second would have been born. People I felt sure would always have just one are starting to announce pregnancies, and it is hard to be suitably happy and supportive. I am happy for them; I just feel more left out than ever.
So far she is happy and never seems lonely, but does want a lot of input from adults when playing. We will have to work hard at the friendship thing, and I also don't find it easy to make friends. I do, however, find it much easier to do on DD's behalf than mine - ie I can start conversations, offer invitations because I feel she needs it, when I would not do it for myself.
Apparently, though, 25% of children grow up as onlies (although very very few in Dorset!), so we are not in a minority. The trick is, I think, to dwell on the positives - think of the things you can do because you are a family of three. Travelling, spending money on things you really enjoy, having pets (we have lots).
Good luck!
DeanyChip - there is a thread for people who live abroad. I can't remember what it is called. Can you look on there and see if there are other English mums near you or if there are people with advice about living and socialising in Belgium?