I've tried visualisation, and imagining his voice/cry and looking at pictures of him, but that doesn't seem to make much of a difference ...

I will have to try the heat pack - I'd only heard of using them for blocked ducts.

And I try to get in as many pumps as possible, but am already doing 1 after morning feed, 2 during work day, and one after his night feed (not after the 7pm feed, but closer to 10pm, to get as much milk as possible before I go to bed).

I don't think I could get another feed in! Unless I woke up overnight to do it...

Thanks ladies!! Will let you know if I get some success