Don't spend so much time dwelling on your emotional feelings. Just set out the task and get on with it.
That feeling of being caged or trapped etc comes from thinking, thinking, thinking. That is the cage you are running around endlessly inside of your own head. Every single book you read about successful people will tell you to use check list of work to be done and checking things off gives you the immediate reinforcement you need to keep on going. Focus on the list, don't focus on your emotions other than making sure they stay directed and on task rather than dragging you onto the endless wheel that goes round and round.
By the way you can break the habit of your brain drifting onto that endless time wasting and energy consuming emotion wheel all the time. All you have to do is teach yourself to mentally say a few "magic" words, they can be tailored to your preference. An example of those words are "stop", "enough", "focus", "get back to work", "its not break time yet" etc. You might have to say it a number of times when you first get started in the practice of switching off that thought train. But before long you will get into the practice of not running on the wheel for more than a second or two at the most. That is because it does not take all that long of a time to teach your brain to shut it off when you start thinking those thoughts that were demotivating and demobilizing you.
It makes zero difference how, when or why you accumulated the possessions you want to let go of. So quit daydreaming about all that stuff and just move on and think about goal results instead of causes. You might well end up letting go of a few things you wish you had kept and for sure you will keep things you later realize you don't need. That is normal, it happens to everyone and it is not a tragedy, it is an annoyance.