Part of the reason I've still not gone solo is I struggle with the flare
That's exactly what happened to me. It was when I realised that I had difficulty in judging height/depth perception that I began to know what to work on, rather than just bashing the circuit and hoping things would iimprove...and in some ways just practising the same mistakes! That's why I asked
pigs are us if he knew what the problem was. Nobody else ever found out for me, but my instructor (the fifth!) eventually taught me to keep the power on through the flare and round-out, then gradually ease it off till we landed. Apparently it was supposed to be a slightly harder technique, but for me it was so, so, so much easier, because flaring at precisely the right height wasn't so crucial.
Later on I realised I could have understood the problem far earlier. After all, I'd always had difficulty overtaking when driving, despite getting my driving licence at age 17 - but I find it hard to judge how far away another car is. The same problem. When driving, I'm just very careful...and of course it gets somewhat better with practice. As it does in aviation.
I don't know how many other people have this particular problem. I do know that if you can fly, but one thing is causing difficulties, you need to identify what it is and practice that, or look for specific ways through or round the problem. A problem identified is halfway to being solved.