Nvr2L8, you have been through a lot it seems. Here are some thoughts:
1) Testosterone – yeah, I would imagine that could cause all manner of issues in a woman. Who is giving it to you? An endocrinologist? Is it because of a documented testosterone shortage in your body? If not, I would be very hesitant about taking it. You are likely right about the weight gain if that’s what your intuition tells you.
2) Weight issues are always going to be more tricky for people with thyroid issues. Why are you taking not enough thyroid meds? Can your endo adjust them? I would get the thyroid figured out if I were you, unless you think it is good now between the meds and the supplement.
3) Your meal patterns are likely problematic for your body. I would get onto a 3-meal a day schedule pronto. Make sure your body knows when to expect food, and roughly how much. This could be a small breakfast, a moderate lunch and a larger dinner; or the reverse – whatever works for you, but keep it consistent. I would recommend you read “French Women Don’t Get Fat” to learn moderation and how to “compensate” if you eat too much at one meal. It should not involve skipping meals, but should be natural. Like if you have a huge dinner out one night and overdo it, the next day you eat all 3 meals, but they may be smaller, lighter. Lunch could be soup and a roll instead of the usual sandwich, that sort of thing.
4) I would not overfeed if I were you, especially based on all your medical stuff. Just eat 3 normal meals a day, on schedule. Go slow.
5) If you can get to sleep before 11, it would probably be better but work down to it. I don’t know about 5HTP but I’ve heard anecdotally some get weight gain from it. Not sure. Can you try magnesium at night for sleep instead?
6) A 2-mi walk a few times a week isn’t bad for starting exercise. If you can add in some weight-bearing exercises, like weights or yoga, it might help.
Hope this helps!