Semen requires months to return to normal, the average time it requires to mature is 74 days, so you gotta be patient.

You should also consume adequate amounts of carb, that will also help with SHBG. T3 increases catabolism, at physiological levels it shouldn't be a concern as long as you meet your energy requirements (that means no more dieting). Eventually, the deiodinases performing conversion of thyroxine (T4) to triiodothyronine (T3) will resume normal functioning.

Standard approach to SHBG includes Vitamin D3. With high dosages it requires some monitoring.

What is your CBC? Iron status?