Throwing in towel
I don't usually post on forums as I'm a bit shy I guess! But the first post resonated with me a little.
I also had a few gaps in my ppl training a few years ago, and I hit a 'wall' when it came to circuits. It was costing a fortune and I just wasn't 'getting it'. I also failed two cross country solos subsequently. Frankly, I'm not used to failing, and it was all rather difficult and frustrating. Looking back, I think that yes perhaps I'm not as gifted as I thought I might be, but also my instructor wasn't particularly encouraging. S/he used to get very annoyed at me, a bit shouty, and it wasn't very enjoyable at times. I switched instructors and the opinion of the subsequent instructors was actually my flying wasn't that bad and I received some encouragement and I enjoyed it more and flew better. My original instructor just taught me to tolerate nothing but total accuracy. This isn't realistic, a hobby pilot. I just want to fly safely. As it happens, I think I now fly more accurately than the average low hours pilot, based on feedback from subsequent instructors, probably as a result of my first instructor.
Anyway, eventually I passed after around 65 hours, which isn't all that many I guess. Whilst I'm no top gun, I'm much better than I was and I've completed an IR(R) too. I really enjoy flying and based on my own experience I would also suggest that you try a new instructor and just try to enjoy it a bit more. Take the pressure off, as others have said. Good luck!