Try some natural supplements and have a panel test done to see if they could be your answer. There are some over the counter supplements that aid in maintaining elevated free testosterone levels. Avena Sative, copper tartrate, magnesium aspartate, zinc aspartate, and vitamin-B-6. There are products that contains Muira puama (potency wood) zinc, magnesium, and Vitamin B-6 in highly biologically active forms that have clinical studies supporting elevation of free testosterone by about 30%.
There is total, bound and free testosterone plasma levels. Bound testosterone, or any androgen/AAS, is inactive and bound by SHBG (Sex hormone binding globulin) and has no effect because it cannot merge with receptor sites. Free testosterone is the only active form and accounts for about 1-3% of total testosterone /Androgen plasma levels. So a total testosterone threshold of 100 MG would only provide 1-3 MG, approximately, of free and active testosterone.
This is quite a bit when you think normal endogenous total plasma levels are around 7MG (.07 MG of free testosterone per day).