I don't know about testosterone levels, but having a new baby introduces a lot of factors that will affect your weight loss and fitness efforts (I'm a father of two). Like you said, you've been sleeping on a chair and eating garbage for a week. If you're not getting quality sleep, your body will feel hungrier to compensate for the lack of recovery and it'll be harder to not eat more. A new baby means you won't get any uninterrupted sleep for a few months to a year, until he/she is sleeping through the night, so try to fit in naps everywhere you can. Back off on your workouts, if you can, to maximize your recovery efforts. Plan ahead with your food options and make sure you have healthy stuff with you at work or away from the house.
If you're concerned about testosterone loss, my advice is to do strength training once or twice a week. Right now recovery and the new baby should be your main goals, just maintain the progress you've made so far. Everything else will come in time. :)