Well, my counselors in the past have told me that after so much time of thinking and coping in one negative/depressive way that it takes just as much time if not more to re-train our brains to think in the new, more positive and realistic, healthy ways.

I would say the journaling, yoga, and returning to therapy soon are great concrete ways. But otherwise, just celebrate any small way that you cope well with a situation. Your job should be understanding about your illness and when you go back, you can congratulate yourself that you were able to return to work, recover, and not let anxiety stop you from returning..that's worth celebrating!
You may not always cope perfectly, but it's important to forgive yourself or not worry too much if you have a bad day and then just continue working and celebrating every small victory.