With time, you’ll definitely get the hang of it. Planning for when you're eating out is really helpful. Another thing you could do is carry snacks everywhere with you and always be confident in your choices. But of all, social situations are probably the hardest part of any diet. Well-intentioned family members, friends, and colleagues may not understand your new ‘strange’ food choices and will encourage you to eat differently with a dose of emotional blackmail.
You can try to, politely, explain what you are doing and why, and if people are open to it, maybe even educate them. But they're not receptive, just let it go. It’s your choice and, with time, they will see how you are thriving. Also, leading by example is often the best way to change minds. How you feel about yourself and your health is the most important factor. Often times, those who are taking less responsibility for their health may want to bring you down. If you tell people you are doing this to help yourself feel physically and mentally healthier, they will understand eventually.