Hi annasmami (and anyone else who's interested!), just wanted to give you an update. DS is now 2.5 yo and finally saying a few words - mama, daddy, hase, outside, other, bicycle, biscuit, and please. TBH, most of them sound kind of the same and nobody but us understands him. He seems to have problems with a large number of sounds, and still doesn't really imitate much at all.
The assessment at the Child Development Centre was inconclusive - they said he was very immature in lots of areas, including physical and cognitive, and that an autistic spectrum disorder was a possibility. We were, of course, completely gutted after being told this, but having read up on autism, and having observed DS's progress over the last few months, I'm getting more and more convinced that he's not autistic. But there is no denying that something is wrong, and it's not just speech. Due to having moved house recently, we had to go on another waiting list, but will get seen in December at the local Child Development Centre and by a SALT. In the meantime, we use lots of sign language with DS and have recently started PECS (a communication system based on pictures), both of which have made life a lot easier and DS much happier.
I now think we made the right decision when we stopped using 2 languages, and it's no longer that upsetting to me, as I'm far too worried about the big picture than to hanker after my dreams of having a bilingual family. Please keep your fingers crossed for us that DS is just a slow developer and will catch up eventually...