Just started testosterone - too good to be true??

I'm 5 days into testosterone therapy, and I'm feeling amazing! Happy, relaxed, singing to the music in my car, patient with my children, alert, energetic. I'm wondering if this is too good to last? I'm also wondering if there may be a placebo effect happening in conjunction with the hormone. I'm curious to hear if others have felt this instant benefit from T therapy, and if so, did it last?? Thanks ladies!!