Belinda, have you tried the things listed in this thread Comforting Tools to Aid Restful Sleep?

I know it's really hard when they are having short sleeps during the day like that and they are still tired when they wake after that one sleep cycle. What time do you put him down for bed in the evening? How many hours does he normally sleep for overnight? Jacob wasn't going to bed for his big sleep until 9 pm at night and would sleep until around 6 - 7am (mind you he would wake frequently during the night) and would have 3 or 4 30 - 40 minute sleeps during the day. He was exhausted, the poor little mite. He was never getting enough sleep. What we did, was to bring forward his bedtime to 7pm and held him out a little during the day to try in an attempt to adjust his sleeping patterns so that he wasn't so exhausted and to try to encourage him to have a longer sleep when he did go down. Initially this meant some crankiness, as we kept him up for say another half an hour after he exhibited tired signs, but with doing that, he would go down and have a much better daytime sleep. It's amazing just how much happier he was, so that half an hour of crankiness whilst holding him out for a sleep, really worked for us. We were helped in this process mind you, in a Mother & Baby Unit. They didn't practice controlled crying which was a relief and practised these kinds of alternatives......

I have had to rock/pat Jacob at times for up to 45 minutes and whilst it's a killer, it does work for him.....and I've found that it doesn't take anywhere near that amount of time now, unless there's something else going on, e.g. he's unwell.