Just remember you're not the only one there with self body issues. You'd probably find that the vast majority of people at the gym have or have had their own body confidence issues, that's why they're there, whether that be they were bullied at school for being fat/skinny/lanky/short or as they've got older they've noticed a belly forming or their other half losing interest.
Some of them may have got over it and just got into going to the gym so still do, but they'll remember and won't judge you. They'd probably applaud you for doing something about it.
For the record I'm now 70kg down from around 160 at my peak. It's as much about diet as it is about exercise, you might find that changing your diet kick starts you on your weight loss which gives you more confidence about going to the gym which is the way I did it. The best thing I found to help change my diet was using a food/calorie tracking app… use it religiously and enter everything you eat, I started weighing everything so that I could record it accurately just the process of thinking so much about the food that you're eating and understanding the nutritional value of it all works wonders. Many of the apps also give you meal ideas or diet plans to follow and can track and plan exercise sessions, the one I used was lifesum, but there are several others.
The only slightly embarrassing moment I've had was while changing, a child in the changing room noticed me and was saying to his dad "Dad, Dad, look, that man's got boobs", to be honest the dad sounded more embarrassed than me while he's trying to shut the kid up.