First of all, this is a terrible terrible terrible idea. Why the heck would you do such a thing? First of all, your sperm could cause your blood to coagulate within the blood vessels sending a clot to your heart and it could kill you. If you keep this up you will probably continue to get sick, and sicker, and die. Again, this is a terrible terrible idea.
To answer your other question, no, sperm does not have stem cells, sperm are not stem cells, and sperm cannot rebuild brain cells.