You need a plan B.

Assuming the number of university professors stays constant, a professor only needs one of her/his students to be her/his successor.

Think about all the students that graduate/get a PhD. A professor may be the promoter of 10-20 PhD students throughout her/his career. Only one is needed as the replacement. The other 9-19 have to get some other job.

Whatever your plan B will be, you have to decide. In a sense it is indeed true that you having a PhD in history or some random BSc in any subject, for many jobs will be just as valuable.

I am in a technical field, and even there people worry about the disadvantages of getting a PhD. For many jobs, there is a disadvantage to having a PhD mindset, even when the job market is good.

I would look into management/clerk jobs in industry/business. You can't learn most the stuff you need for that in school, and employers know that. They just need the right type of person. And your degree will show them you have the tenacity to complete a degree.

If you are not the 'right type of person' and your degree is bad, you don't have the right connections and you aren't at the right place at the right time, it may be very difficult. That's why I think it is dangerous to just tell people to 'follow their dreams or else you'll regret it'. Nothing sucks more than being really skilled, passionate and educated, but not having the opportunity to use what you learned. You can have regrets either way.
In fact, there are people who played it safe, have a boring job in a safe industry, and they have regrets. They may have had even more regrets if they had to go through life as an unemployed academic.

If you want to go for a PhD in history, I think you have to make sure you are above average. You must be willing to move to another country every two years for the next 10-20 years, and crazy stuff like that. Most people that become academics now will never get a permanent position, ever, as institutions are moving away from permanent contracts even for top researchers.