Marriage is always 70%/20%, right?
Well I think right now you are the 70%.
I think you need to be more assertive. Call the doctor and make the appointment, and TELL him he is going.
Tell them on the phone that it is for low testosterone, and to adjust his anti depressant. For this one instance, I would even push my way into the actual doctors visit (normally I don't think this is ok).
If that didn't work I would request some of the doc's time at the end of the visit to share what is going on with husband. The doc will want to know what you see going on at home.
Part of depression is inability the to make decisions... You don't know where to step first, and then if you do, sometimes you are just physically unable to do so.
I think for the next few months it is ok to be assertive and take control of the situation. If the medical adjustments don't clear this up, if you run out of patience or don't feel it has been resolved in a reasonable amount of time then I would contact a marital therapist.
Best of luck to you!
ETA: when you start counseling, make sure you let the counselor know you feel he just "plays along". It will help him/her help you.
ETA 2: who is prescribing the antdepressant? Most psychotropic medications are only effective when paired with a mental health therapist who is seen regularly. Just something to keep in mind.
Make sure you take care of yourself!
Hope it works out :-)