I can bet my bottom dollar that those 3 good weeks is not because you had taken vitamin tablets. You had a window dry and it lasted 3 weeks because you have gone far into the healing process. You are now entering a wave and yes it feels like you are back at square one but I promise you are not. You will be well again. The fact you went 3 weeks feeling good is testament to this. Your brain can balance itself again and it will.