After almost two years the work is back on track.
During this time tried Unity and Unreal Engine. Unreal Engine, in my opinion, is just not suited for programming - when some error crashes UE, you need to fix it in Visual Studio and then restart UE. It's just crazy. Unity is just slow for what I want.
Then, I've tried to move to DirectX 12 (many years ago had experience with DX9). But it's so complex. First, I thought I'm becoming too old to learn new stuff, but then I tried 11th version and it's much much simpler. So, for now, I will stick with DirectX 11.
Also for these two years, I've been learning drawing, 3d modeling and music theory so I will make all assets by myself.