I had a similar dilemma (and still do to an extent) & my numbers...

I had a similar dilemma (and still do to an extent) & my numbers are close to yours (probably rose from <10% of my portfolio to >20%) - I sold a quarter of my holding to reduce this risk & moved to growth/yield. This has already cost me, however I'm comfortable with my use of the proceeds. I've had a fortunate year though, with a lot of my portfolio going up slightly limiting the proportionate gain APT has on my portfolio.

I don't really know my next sell point unless something goes bad & I can use a capital loss to offset some of the gain.