For many people, it would be difficult to move to a new town and reestablish their careers. Depending on the type of career, it may be impossible. Business owners, for example, often establish themselves in a particular town and “make a name” for themselves. If they were forced to move, they may never be able to reestablish their careers.
For others, they might have to move to a new area, because that would be the only location to find employment. They may not want to move but they realize that if they didn’t they could not work.
You entered into this relationship with the full knowledge that your boyfriend had no plans on moving. Now you have changed your mind. You did not state where you wanted to move and why. Based on your letter, it does not seem as though you have a particular area that you liked to move to. You simply don’t like the idea that you cannot move, in the event that you would want to.
The old saying “the grass always seems greener on the other side of the fence” may accurately represent what you’re feeling. That saying essentially means that often circumstances seem more desirable, even though in reality they are not.
Healthy relationships are based on much more important factors than location. Perhaps you’re not outgrowing the town but in fact you are outgrowing the relationship. You have to decide whether or not this is a relationship that you want to continue. Consider consulting a therapist if you have difficulty making that determination.