I was in a similar boat mate. I'm the same height and weight as you.
Do you use a gym? If so do they have a wight assisted pullup machine?
I used to one get to grips with the technique. Started with them quite easy then decreased the weight week by week so I had to try harder.
Can now do 3 X 10 without too much trouble. Took a couple of months to get there.
thanks for the replies. In my old gym they had a assisted pull up machine, but my current gym has no steps so you have to rest your knees on the platform which is main reason not bothered with it so far.
guess its just a case of persevering with it