What Ryan and Polo said. It is possible in many cases to go on T for a while, get off it and have kids, then get back on, a la "The Pregnant Man" featured on Oprah a few years back.
This could be an option for you, but it would definitely be important to bring up to your transition team (gender therapist, any other therapist, endocrinologist, etc) before going forward in any direction. The endo especially would be able to help sort out the realities of your body and whether that would likely be possible for you individually.
Take care of yourself - mind, body and spirit. You may have to do some soul-searching to really prioritize what is most important to you, and the risks and benefits of both staying off T or going on it. If you are seeing a gender therapist, they can probably help you through that process of introspection.