Thanks for sharing about your experience - it takes courage. I can relate to the pressures of changing careers and life transitions adding to anxiety. A few thoughts from my own coping journey:
Focus on one day at a time and small wins. Comparing to others just adds stress. You've come so far already in getting your cert back - that's huge.
Keep close your support system. For me, daily exercise, journaling feelings, and friends/family who understand without judgment help so much.
Maybe look for flyer mentor you vibe with, to ease worries about coworker perceptions over time. We all have things we navigate. You've clearly got this!