ok, so the temptation here is to flame you back to the stone age, but I'm in a benevolent mood.
DO NOT JUST INJECT TESTOSTERONE WITHOUT KNOWING WHAT YOU'RE DOING.
That would be a very bad idea. When you inject testosterone, a whole heap of shit happens to your hormones, and you need to understand this in order to use the drug safely.
Things you need before you even consider injecting that test:
-An Aromatase Inhibitor (AI). When you increase your test levels the body responds with a rise in oestrogen. High oestrogen is not good for you and can cause all kinds of problems from high blood pressure to growing breast tissue. An AI stops this process. Unless you want to have a heart attack wearing a sports bra someday, you need to take care of this.
-A Selective Oestrogen Receptor Modulator (SERM). When you introduce exogenous (think "outside") hormones into your system, then your body's endogenous ("inside") hormones turn off, because the body doesn't need to make any of its own. When you come off steroids, your priority should be to get your body to start back up with its own testosterone production. A SERM helps your body to do this.
Please be aware that even if you do use an AI and a SERM there is potential for lots of things to go wrong, so educate yourself on what these things are, learn about all the different drugs and why you need them, and then once you're informed and ready, you can make the decision to use the hormones.