Multiple disorders

I am 32 yrs male. I have multiple disorders.I would start with Erectile dysfunction.I feel my penis size is reducing. Earlier when I was around 20-25, I used to feel it was bigger in length. I had near about 6 inches but now it is only 4 inches. Regarding erection,these days it does not last long except for few seconds. Even the sperm quantity has also reduced a lot. Weekly once I masturbate but I get one or two drops only and that too it falls off the tip. Now closer to it, my testis size has increased a lot. Does it happen that since the testicles are increasing, it pulls down the muscles and skin of the penis?
Even my complete body has also shrinked a lot. I mean my hands, shoulders, my thighs, my legs. It would sound weird but my height is also decreasing. It has happened such a way that I cant even wear my clothes which I bought a year ago since the pant's lenght becomes more and the legs become loose. Even my shirt also the same. It feels like im wearing some one else's shirt.
When I go to a doctor, they first ask me to do a sonography for the testis. but the reports come normal. but it is me only who know the difference between the past and now.its so shameful when I sit somewhere (everyone can understand what I mean to say).
regarding penis length, doctors say size reduction does not happen and 4 inches is fine for sex. regarding erection, they ask me to take regularly sildenafil citrate (but I get a lot of side effects from them).Regarding height, they just laugh and say it does not happen. about body structure they get no clue.

I have visited most of the hospital in Bangalore and Mumbai but everywhere I get the same response.
I am really worried what is happening to me. If I am closer to something very serious.
Please help.

(I smoke regularly around 8-10 cigarettes and drink once a week 180ml)