Need Operational Advice

Hi all, I an ex-MBB project leader who has moved into small scale ultra-luxury real estate development (Europe) over the last years. So far I completed one transaction where I invested 1,2 Mio. EUR and and made 1,2 net profit after taxes. It took 4 years and incredible effort to complete (ultra-luxury perceived renovation for very low cost, value driven by design, I studies architecture and highly regarded fine arts university way back). 

No I am in completion of a minimalist ultra luxury single family house where I invested 2 Mio. EUR and brokers I trust valued it for 5,5 - 6,5 Mio. EUR I assume I can sell for 6,2 Mio. EUR. Reason for the huge profit is extremely clever plot selection with long search and minimalist design which in a nutshell costs nothing and looks incredibly expensive. I will go on the market in september. I started this 4 years ago.

Now I am looking into aquiring a historical property for 5 Mio. EUR plus 1 Mio. in re-design and renovation, that I think I will be able to sell after my value add for 10 - 12 Mio. EUR in 3-4 years.

Nevertheless I feel so exhausted as this kind of development is incredibly consuming. Buying the right property is difficult and risky and I apply a very detailed techical, lega and commercial due dilligence plus I need to have a vision for the place that transforms it. Then I need to do all the design in icredible detail, then I need to find people to perform the work, I need to understand every step extremely detailed guide and control them and pay them as little as possible. 

I know I have to continue this, but it feels so exhausting and I do not know how to make it more bearable again. I do this all on my own, no employees.