Losing a pound a week is a great way to start, so congrats! I dont know if you are eatting anywhere close to that 3400 calories a day, but that seems like a lot. Like Kati said, you may want to speak with your Dr. about a weightloss program. If you think about it a lot of body builders are consuming that many calories.
I am trying to add a few pounds to bulk up at bit, im 5'8'' and i weigh around 165, id like to get to 170-175. That calculator said i needed to eat almost 3000 cals a day. So apart from my full time job, id need another just to consume that many calories. Im willing to bet if you went down to 2500 or even 2200 cals you'd get enough nutrition(sounds like your eatting healthy).
You can even keep a food diary of what you eatting so you know how many calories, protein, fat, carbs, etc that your consuming. Often times you may think your eatting enough but when you look at it your off by several hundred calories.
Losing a pound a week is a good pace and before you know it you'll be at your goal weight and just maintaining all that hard work!