Just finished! I actually got started a different way (unhelpfully for me, one of the Js was my LOI - in fact for a while I thought I messed the whole thing up because I couldn't think of any word that fitted the crossers), Z and Q were for a long time the only ones I had in, but then the P and the H together led me to the X and I was away.
I was quite close to giving up, but once I got a few in the grid I was flying, so keep going!