You aren't the only one to be watching it. I used to when it was on the BBC, but, of all things, I missed the last episode and have never ever seen it. As such, I am determined not to miss it this time.
ITV3 have actually shown it from the very begininning, and as with other series, they have ALL been shown in their entirety. GS is on the fifth series at the minute, with one more series to go, so I should imaging the last episode will be shown in a week or so.
However, ths link
http://www.goodnightsweetheart.co.uk/ actually gives a transcript of the final episode should you want to look.