You may not be the person you used to be. Maybe too much junk has been dumped into your brain. Junk from negative people. Junk from TV, Radio, iPhones etc. Filter out the stuff that gets put into your brain.
Listen to positive messages; remove pictures, videos and TV shows that deliver negative information. Set boundaries for people, even positive people. Know your limits and pace yourself, go your own speed.
Put small soothing actives in your schedule throughout the day. Small things to look forward to help you relax and stay calm. Looking forward to that cup of coffee, or just a short walk can really help. Read a positive message, put on some headphones and check out for a few minutes.
Managing the world around you helps you manage yourself.