How heavy is a glass of water?
Its weight ultimately doesn't matter. It depends on how long you hold it.
If you hold it for a minute, it's not a problem. Hold it for a day and it will become heavier until eventually, it causes your arm to ache and feel paralyzed.
Your worries are like this glass of water, it's important not to think about them all day. Set aside 10 minutes a day for 'worry time', then get on with your day.
Remember to put the glass down.