Okay so next day I got Gpu crash/d3d device removed error again, but after working for a while with a piece of a scene. I guess this error is a curse. Seems like I need to save every 30 seconds and continue working. I have couple more solutions from forums that I saved, will try them later.
EPIC GAMES TECH SUPPORT please take a look at this error, a lot of people are struggling and getting bad reputation after missing deadlines because of this error and etc…