Is that normal ?

Royal Dwarf 250w HPS
My plant is close to 3 months and yeturday started yellowing before that it was healty as f*ck ;D
nutrients deficiency or plant going to end ?

that happened in one day?

There is no way all that happened to your plant in 24hours, looks like you over did it on the nutrients with the cremated leaf tips, unsure as to what is going on with the rest of the plant.. maybe someone else can help you there.

yesterday was barely visible yolk, but today already looks like this

You have nutrient issues - go to "Growweedeasy.com" for pictures of plant problems; you will find that one