You need to find a TRT (testosterone replacement therapy) clinic. They are all over the place. They will run a full panel blood work and put you on most likely Testosterone Cypionate weekly injections between 50- 200mg. It's very easy and simple to do at home and will improve your mood, energy, and libido. The testosterone oral gel is an option as well if you prefer to not use needles.
You may also need an Aromatase inhibitor pill once or twice a week to keep your estrogen low, and some guys also do HCG injections to counteract negative sexual side effects of testosterone.
TRT can really improve your quality of life. Good luck!