There's nothing unnatural about what you're feeling. Sometimes it will be better and sadly, sometimes it will be worse. I think the first step is to realize that it's natural and there is nothing wrong with you.
Second, I'm going to be real blunt here and this isn't going to help me in any interviews but it needs to be said. Ask yourself a serious question, "Is this job worth my suffering?". If you need time away to go on a walk, learn how to paint, read a book, hiking, or just working on a side project, you need to ask for it. If you're lucky enough to be a job that will understand that then take advantage of it. If your job makes it more difficult then don't stress but it might be time to try to find another job. If a company asked me to work 60+hrs a week I would laugh. If I wanted to work 60 hours, they wouldn't need to ask. Also it's very freeing to take your job less serious and in all honesty, I see improved performance when I'm in that mood.
Some people say pick up a non-related hobby... I think it's simpler than that, really. Just think of what you want to do at any given time and go do that in your time off. My problem in the past has always been making excuses to not do the things I actually wanted to do in my spare time.
There's a bunch more I could speak on this but I think this is fine for now. Go do something fun. Do what you want to do.