In reply to swifty:
You're strong enough, now you need to learn to climb
Getting up stuff a few grades harder isn't about doing the moves, they're rarely that hard, it's about getting into the right positions for the moves efficiently and quickly, learning to take the load off your arms, learning how and when to rest even if only partially and when to push on. You also have to lose the fear of falling so you're totally uninhibited when it's safe to be.
I'd suggest taking 10-15min as part of your warm up at the start of your session to simply move around on the wall, mostly easy moves on mostly vertical ish terrain taking in some corners, grooves, whatever the wall has to add interest. Don't worry if you have to step off and walk to another section occasionally. Take your time and focus on moving slowly and deliberately without getting physically stressed, on each set of holds find the grip and body positions that free the limb you want to move and facilitate placing it efficiently under total control. Try the moves facing in different directions, don't be afraid to get it wrong or fail, just note what works and doesn't while maintaining control. Experiment with the wall's features and body positions that allow you to rest, to free up both hands or shake them out sequentially. It's all about learning to move smoothly and deliberately on easier holds so the various positions and gestures you'll need later when pushed are deeply ingrained. It's also a pretty good start to a warm-up and useful for injury prevention.
FWIW I've never been able to use a campus board let alone fly up one and it never really held me back as much as my fitness did.
jk