One possible cause of micropenis is a mutation of gene SRD5A2. This gene encodes the enzyme 5-alpha-reductase-2. It is responsible for reducing testosterone to DHT, i.e., 5-alpha-dihydrostestosterone, the most potent of male hormones. Trans-cutaneous DHT patches have been used to treat this condition.

Remember, we all start out female in the womb. In a sense, all males are transgender females. In your case, I think, all you need is a little medical help, to get the job done.