First, comparing yourself to others is a recipe for unhappiness. I guarantee unhappiness and ennui is part of every day American life as well. I’m living it. I don’t know why I get out of bed each day other than to provide for my family, and I’ve been out of work for 5 months. Feels like waiting around to die, honestly. Maybe you think being in America would solve your problems, but it just presents a different set.
Second, accept the things you can’t change. If you can’t fix something, let go of worrying about it. Easier said than done and beware of telling yourself you can’t change something when you can, but if there is something you can’t fix, let it be. I know you said you’ve gotten that advice already. It’s easy to hear but hard to accept.
Third, set yourself some achievable goals. If it’s exercise or reading a book or painting a picture. Especially if it’s a step toward fixing one of those things that’s big, but not impossible to change. I’ve seen people build houses with their own hands over several years - one piece at a time. I have a friend who is mid-40’s and getting her 4-year degree. One class per semester. She’s on class three now. Eventually she will get there. I’ve set some goals to improve my physical health. It’s a long fucking road. I lost 60 lbs. about 8 years ago. Gained it all back. Now it’s time to tackle it again.
Fourth, make yourself look for good things. It’s a beautiful sunny evening here after days of rain. I didn’t achieve much today, but I can appreciate the warmth on my skin and the blue and white sky. My wife is out of the house taking a crafting class with a friend and I’m happy for her because that doesn’t happen often. I have some interviews this week and maybe one will be the right fit. Whatever the good things are in your life, find them and spend a little time just appreciating them.