I have had gynocomastia since I was 11-12 (big puffy nipples with breast tissue underneath), and have always been conscious about how I look in a shirt. So I think I have too much aromatase activity, so I ordered some simple aromatase inhibitors from iherb, like chrysin and DIM, Although there are many compounds and foods that work. I've been trying to get to a low body fat 5-7 percent, but it's been very hard, and I'm at 10 right now so I think it's necessary to address the root cause, not the symptom which is low T.
How long has it been since you said you overtrained from exercising? Ive had that problem too and could not workout for nearly 2 months from overtraining (simply no desire to lift heavy weights). If you have elevated cortisol still from that, it could be a huge factor in your diagnosis. I don't know the full story, but I recommend some sort of adaptogenic herb. Also how would you rate your drive to exercise? Do you feel as fresh as you did before?
Rhiodiola Rosea - very good for the adrenals, and the entire HPA axis, which is often devastated from overtraining
-stimulating in low dose, sedative in high dose
Ashwagandha - another adaptogen for restoring the HPS axis, but a gentler less stimulating one
Reishi
Ginseng - supposed to be a stimulating tonic herb to balance hormones
Tribulus - boosts the testosterone more than any other herb, almost, but could be too stimulating, I've had roid rage on it and I don't know if that's helpful if your HPA axis is down.
Make sure to get in the right fats. I eat plenty of cheese now because I feel really amazing when I do. When I eat less saturated fat and too much plant fats I do not feel nearly as good.
If you go to a local herb shop, you can probably get a decent amount of any of those herbs. I got an ounce of cut up rhodiola root for 4 bucks and it lasted about 2 weeks for making tea everyday.
I'd recommend mindandmuscle.com/forum - they could give you more details on how to solve your problem based on the chemistry of everything, but they're not into healing through diet, so they'll recommend drugs.