Hi Sabs,
No advice as such I'm afraid, but just wanted to say that I'm going through pretty much the same thing with my LO at the moment too.
Although NWs have eased off the last few nights, she still wants me to stay with her til she's asleep at BT and naptime (although fine if some one else puts her down). She's cutting her last canine and the other three made her more clingy too so I think, for L, the cause is teething but also a big dose of developmental SA.
In the past, when she's been 'difficult' to put down (always due to teething and/or SA), WIWO has worked fine, she's not got *too* upset and it's not taken *too* long. But this time it's quite different - she just won't fall asleep without me (if I am the one who puts her down).
In the birthclubs some one told me SA often peaks around 18 months. I googled this and found lots of sites saying this too. So, for now, I'm planning on giving her whatever reassurance she needs to fall asleep (usually she just wants me to stay with her until asleep, but once she's drowsy I don't need to be holding/touching her at all, just standing by her) and will then use GW/WIWO (whatever works best) once this SA phase is over.
Hope things improve for us both soon!