One thing we had to do even in the 1980s and 1990s was to move out of town to areas that were being developed. On two salaries, ( both higher than average) we bought our first small house on 100% mortgage paying 17% interest knowing we had to buy and sell about every two to three years to get to a point where we could afford something we wanted in a better area nearer to work etc. At times we hardly saw one another as we were either doing over time or travelling my commute was nearly three hours each way for a while. It's what you do,and I thinking what people who want to own their own homes have always done with no help available from family. Another friend Sandusky his parents could afford to buy him and his wife a tiny one bed flat.
don't forget a good salary back then was about £5,000 a year and a small semi was about £40,000 and you could only get 3½ x joint salary as a mortgage. I think you might need to rethink you plans or find a partner with a really good job but you can get where you want to be, you may have to make compromises will you work towards it. btw. House prices are also high because of fascist of land to build them, if we adopted the dutch urban model of taller houses with a smaller footprint and little or no garden we would pay a lot less. We won't because we are conditioned to expect our houses to be a certain way.