Intersesting problem. I wish I could understand what you must be going through.
I think the key is weight training and nutrition.
You have figured out that you must eat more than you are burning. But by strength training you increase your metabolism and burn more calories. and so on. the cycle never ends right.
the weight training must be a balance, a very fine line, between encouraging muscle mass and stimulating your metabolism to burn more calories. I feel that a balanced strength training routine (like you described) using higher reps, 12 -15 repetitions, may increase muscle size and mass quicker than using heavier weight low rep workouts. But strength training is a long term commitment and usually not a way to win a short term bet. The first gains you will notice will be from increased water and fluid retention in the muscles.

One of my collegues, a tall skinny basketball player, says to plan your daily meals and stick to the plan. When it is time to eat eat what you determined you need. Not Hungry to bad. 5 meals a day. He says it is not fun, but it worked for him.
Can't wait to hear what Carl has to say.

B-