Found this from another forum.
Propecia, like Accutane is a class of drugs that change your DNA on a cellular level for the rest of you life. That being said there are a few things that you can do to change this. We know that propecia effects the adrenal glands on a cellular level so more than likely the brain fog is adrenal fatigue. We also know that propecia might change proper testosterone function indefinitely, so to try to overcome this, zinc, and boron need to be supplemented to make proper testosterone. You would also need to do light weight training three times a week, wear boxers instead of briefs, and take supplemental protein in the form of whey protein. Also make sure your vitamin D levels are between 70-80. Finally, I would suggest limiting ejaculation to only once or twice a week for the time being, and only through sex if possible.
As far as sperm production L-Carnitine and R-lipoic acid should increase the quality of your sperm.
Maybe try bio identical testosterone replacement therapy?
Finally, I would consider supplementing calcium d glucarate and DIM to lower an excess estrogen you may have.