I fully understand… most people have those thought. But… let me tell you… you just have to get used to it and those thoughts will go away. Like you say already.
Eventually you deserve some day offs and you can spend some money on you. The vacation. Try some weekend city trips. It will go away.
My mind is never free either… always thinking and wondering. But going out and about, on holidays or walks in nature helps. It will switch off.