What Are The Effects Of Taking Testosterone Injections?

Question: I am 42 years old. My sex drive is not what it once was and my wife's is much higher then mine. She would prefer once a day, but can deal with once a week. I can go 3 weeks and be fine.

So, I started talking to my P.A. About it. He started giving me androgel to help. He said 3 months one and 3 months off.... This did help along with some trial pills that the pharmaceutical companies gave out....

I went to see an internal doctor. During the consult, she asked if we wanted kids. I replied "we are in our early 40's. If it happens, great, if not, ok." She mumbled to herself "no kids" while taking notes. She ran all sorts of tests. Took about 1 1/2 mo this for all my appointments. Long story, she diagnosed me with "empty sella". She did explain it. She began a treatment of nebido testosterone injections. 1 shot every 3 months. I've had 2 shots now.
I read that these treatments basically "shut down" the sperm producing organ preventing us from ever having kids if we wanted them.... is this true!?

What can we do to get my sperm back and maybe get the wife pregnant? Seems I'm shooting blanks now forever.