Welcome!!.
Sounds to me like a low dose of hormone replacement therapy would be a good place to start and I would think your doctor would be up for this with all of the LOW T commercials on TV now.
HGH is not a steroid and many take it to gain lean mass but nobody ends up looking smaller as a result. Lean and small are two different things. Lean mass can help you look tighter even though you could be heavier than someone lighter without the lean look. HGH creates more muscle cells as well as adds to your body surface hence why many BB's like to use it.

First step would be to get a full male hormone panel taken. Then post up your results for the members to chime in. Meantime hang and keep learning. You came to the right place!