I do not know of a testosterone formulation approved for IV or nasal. Only for IM which is into the muscle before absorption. Some doctors will allow Sub-Q (in the fat) because several studies have showed it also gets absorbed in fat but at a different rate.

Shrinkage is not as bad as you would think, in my case maybe 25%. However, my doctor also prescribes HCG to be injected IM bi-weekly. HCG is an analog to LH - the signaling hormone that tells the testes to produce testosterone. As a result mine are still producing a little bit of test to keep their size and prevent atrophy (I am still fertile as a result).

Acne pops up when dosage is going up or down but tends to go away if you maintain a stable dose and blood level concentrations (aka dose timing) for a long period of time.

Most people in my family suffer from depression, and I have in the past. I think most of mine was caused by anxiety though. SSRIs when I was a teen never did anything for me. I now am fine with no drugs for it though. If yours is based in anxiety I strongly believe it will help.