First off, if it was your first dive for a while, for some unbeknown reason probably a little bit of stress everyone needs a bit more weight to get down.
Then what kit are you using, a S/S Back Plate will shed a lot of that weight if you haven't got one already. Neoprene drysuits take a lot to sink so if you have a neoprene suit maybe sell it and swap it for a cordura drysuit.
Last comment of all if you haven't done much diving you will find over time and with natural progression you will use less, if you need weight to sink, as long as you aren't using too much then thats what you have to take.
Oh and just thought try a 15ltr tank will help shed a few more kilos.... Hope that helps
