You can't change other people. You can only change how you react to them. So, you can allow yourself to get stressed out over a situation you can't control or you can try to stay more calm.
I know that's not easy when people are slamming doors, but you have to do your best to turn the other cheek. Some people engage in these types of behaviors because they enjoy the attention. She may be experiencing a lot of stress and she could be an idiot.
As the old song goes,"accentuate the positive and eliminate the negative". Give yourself credit for eating right during the day and don't beat yourself up because you're stress eating.
What to do ? Find others ways to reduce your stress or vent your frustration that don't involve food. sit and have a cup of tea. In fact, why not ask the neighbor downstairs and see if she'd like a cup of tea and a chat. She may be acting out because she too is under unusual stress. Maybe she needs a cup of tea. I don't know why you're neighbor is acting out.
But I do know that you don't have to turn to comfort food to deal with the stress. there really are better ways to cope. sit and have some tea. take a walk with your son during the day. listen to some relaxing music. don't escalate the situation. that doesn't help. Be calm. Being calm will do more for your stress than eating extra cookies or hips.
Do you have a gym membership ? keep going to the gym. Studies have shown that a regular exercise program can help reduce stress as well as depression. Also, do your best to eat more healthfully. Here's something I've learned from my own years of yo yo dieting and it's this,"if you eat crap, you'll feel like crap". If you're under stress, now is the most important time to eat right.
You might find this Spark article on emotional eating helpful. www.sparkpeople.com/resource/wellness_arti