Could I have testosterone deficiency/hypogonadism?

Hello,

My name is Gary, 36 years old, from England, UK.

From the information I am about to provide, I would like your opinions on whether I am testosterone deficient:

The volume of each testis is 11mL (11 cubic centimetres), according to ultrasonography. Is this a normal testicular volume for a post-pubertal male like myself? There is no size discrepancy, despite the fact that I have a moderate varicocele in my left testis.
The volume of my prostate is 13mL, as determined by ultrasonography. Is this a hypotrophic or atrophic prostate? The prostate and seminal vesicles are dependent upon androgen for normal function, so logically, a testosterone deficient state would result in smaller prostate volume and reduced ejaculate quantity/volume (which I do indeed experience).
I have diagnoses of low bone mineral density. Some hospitals have diagnosed lumbar osteoporosis, whilst others have diagnosed lumbar osteopenia.
My facial hair is slow growing. I cannot get a full, dense beard. I have a couple of strands of hair on my chest and underarm regions. Pubic hair is present.
Penis is 11cm when erect. Is it possible for a testosterone deficient state developed long after puberty to result in a gradual reduction in the flaccid and erect penis length? It makes sense to me, since the penile tissues have androgen receptors and penile DNA synthesis is impaired in the androgen deficient state.
Erection-wise, I can never achieve a rigid erection. With manual stimulation, I can get a semi-rigid erection, which subsides quickly after stimulation is stopped. My sensitivity to erotic stimuli is impaired. In other word, I have low libido. So, it is very difficult for me to get a satisfactory erectile response from mental or visual erotic stimuli alone.
Morning erections are variable. On some mornings, I have weak, semi-erect penile tumescence, whereas on other mornings, my penis is completely limp/flaccid. When I do wake up with some degree of morning tumescence, it can hardly be described as a proper, hard erection.
I sometimes wake up at night with my bedsheets drenched with a cold, odourless fluid, which I suspect to be sweat. No 'hot flushes', however. What is unusual is that, the sweats occur even on cool nights of low humidity.
I am still a virgin. I have never had any sexual relationships or experiences of love and intimacy with the opposite sex, which bothers me immensely as you can imagine. I attribute this sorry situation to impaired sex-seeking behaviour and motivation secondary to many years of undetected and untreated testosterone deficiency. Could I be right?
I suffer from depression, low energy, apathy and social withdrawal. My personal hygiene has deteriorated, which could be a manifestation of depression.

Could testosterone deficiency be the underlying cause of all my issues?

You may very well have an issue, however, the only way to know is to have your levels checked. You need to have both your Free and Total testosterone levels checked. That's the starting point. Get those numbers and then you'll be able to start answering questions and finding solutions.