Low libido. Can it reduce sperm counts?

Hello sir I 31 year old married man from 1 year.My problem is erectile dysfunction and very low libido.i do not get morning erections and when I try to have sex with my wife I lost my erection suddenly. I have high cholesterol problem and my b.p levels are normal and my weight is 96 kg height 6"2. My testosterone levels are 290 ng/dl,my thyroid levels and f.s.h,s.h,prolactin level are normal,my sperm count is 66 unit. I always feel low in energy and demotivated. I have fat on my chest and abdomen and less body hair and facial hairs. I am suffering erection problem from 4 years.I went to a sexologist he said I have to go for testosterone injections. Now please tell me 1.why I am suffering from low libido and erections problems? Is this hypogonadism? 2. What are normal testosterone levels and are my testosterone low? 3.are testosterone injections good In this problem and for much time I have to take injections? 4.are there any side effects of this?can it reduce sperm counts?