Does anyone have any tips to help me better access my own feelings in this way? After I have left the house, how do I determine if I feel better? If I don't get the job, how do I determine if I feel bad about it? Etc.

Focusing. Learn to locate feelings in your body and learn to put labels on emotions.

Having QS rituals where you put down an estamation of your internal state every day. I for example write down my dominating mood for the last 24 hours and a few numbers.

As a weekly ritual it's also possible to fill out longer questionaires such as http://www.connections-therapy-center.com/upload/burns_anxiety_inventory.pdf .

It's like a muscle. If you train to assess your internal state you get better.