As far as testosterone levels are concerned as a cause of ADHD or ADD no papers have been published till yet so no proof. Its written on some forums only and patient experiences. So scientifically no proof and one more thing comes into mind that women have very low testosterone if it was the cause then women will be going mad with ADHD :D.
If you want to get tested then do get your thyroid hormones checked TSH, Free T3 and Free T4. For serum Testosterone levels it's your choice I would advise against it, but you want mental peace as you read it somewhere and now cannot stop thinking about it then you can get your testosterone levels tested.
First line treatment for adhd is ritalin or dextroamphetamine(not available in pakistan). If they fail we shift to NRI like atomoxetine(attentra, strattera). But many physicians start with atomoxetine as its side effect profile is way better than ritalin.
Jumex(selegiline) or other antidepressants especially tricyclic antidepressants have been used for ADHD but are not FDA approved. And FDA is the most authentic source when looking for drug approval for particular disease treatment.
Problem I am seeing here is except ritalin and jumex you have never used any drug for a long period if I am correct. Any drug for ADHD will show no improvement until 2-3 months of use and that also will be 20-30% improvement but long term drug use with psychotherapy for about a year will show marked improvement. My advice stick to one drug and please DO NOT experiment yourself with drugs it's not childsplay.
Go to a good psychiatrist or neurologist stick to his treatment for 2-3 years emphasize on getting psychotherapy and then if no improvement change your doctor.