If the lack of natural light is affecting you, SAD (Seasonal Affective Disorder) lamps are easy to find.
Trying to generate sunlight that can fill a room like the sun is going to use a lot of power and generate heat. Also, the DIY youtube versions don't feel very realistic to me, it's probably a much harder (and expensive) problem to solve than just a fresnel lens.
edit: Watching another youtube video, it looks like the DIY versions are missing the "blue sky effect"
i saw one with the blue sky effect too.. i think he made essentially a narrow fish tank and then added some dish soap or something to scatter the light like the sky would
Trying to generate sunlight that can fill a room like the sun is going to use a lot of power and generate heat. Also, the DIY youtube versions don't feel very realistic to me, it's probably a much harder (and expensive) problem to solve than just a fresnel lens.
edit: Watching another youtube video, it looks like the DIY versions are missing the "blue sky effect"