High cortisol levels can have a negative impact on testosterone production. If this issue is resolved, while it may very well help your situation it's impossible to say off hand how much. Will it be enough? Again that's impossible to know. You'd need to first find out if you have a cortisol problem. It does happen, but if I had to put money on it I'd lean towards you being non-responsive to transdermal testosterone simply because this is more common.

Injectable testosterone, this scares a lot of guys because it has the word "Injectable" attached to it and in all honesty it seems crazy. It seemed insane to me too at one time but once you've done it a few times it becomes as simple as taking a drink of water. Most guys laugh a little at how simple and easy it is. As for the testosterone itself, testosterone is testosterone regardless of the form of administration, naturally made by the body or bought from a pharmacy. I have heard some doctors say injectable testosterone is more dangerous than say cream or a patch but there is no basis to this claim. Once the testosterone is in the body, and it's not active until it's in the body, once inside you're left with the same identical testosterone.