I have a few things I always do when I’m feeling anxious about going to the gym after a break.
First, I’ll workout at home as long as I need, to get back to feeling a little more confident with my body. Once I start to go back to the gym I always wear headphones to keep the outside world out. I’ll wear an extra layer of clothing like a bigger sweatshirt and loser yoga pants. I dunno why, this just helps.
Also if I’m really feeling anxious at the gym I’ll just stick to cardio machines. They face a TV, I can kinda be distracted by my phone, everyone that’s on them is kinda in a trance themselves and just focusing on what they’re doing.
Once I’m feeling comfortable to go to the weight room area, I’ll stick to exercises that I feel good doing. If I don’t want to stick my big butt out, I’ll skip squats, lunges, deadlifts etc and focus on leg press machine, or arm, chest, back exercises.
You could find some things that work for you to ease yourself back into it.