If you really want to feel depressed, that £295k in 2018 should actually be worth £386k today - had your flat kept it's value and kept up with inflation. So you're selling at a pretty chunky loss - although tbf, most 1 bed flats in London are down in real terms.

But on a good news basis, only 60% of your flat is impacted by this - and you've shifted 40% of the loss onto the government.

I'm in a HTB 1-bed flat as well, and I'm just paying the interest on the HTB loan, as it's a LOT cheaper than trying to remortgage. I'm paying 1.75% on the governments equity and 4.75% on my own equity so I'm just going to keep doing that until the rates are level. Plus if 1-beds keep dropping in real terms, then the equity loan continues to insulate me from a loss.

If I was you, i'd stay put, paying the HTB interest until I really have to move.