It most likely means that your boyfriend doesn’t feel that you are worth the effort to take out or hang out with outside of school.
You may be his girlfriend at school because he wants the social benefits that come with that, but he may not care all that much about you outside of the school environment.
If you have noticed that he still hangs out with his friends, even though he keeps telling you that he is too busy or too stressed to take you out, he is showing that he prefers the company of his friends over yours.
Being that he has persisted with this type of behavior over the course of two months, all you may be to him is someone who helps to elevate his social status at school.
This may be all he cares about.
You should break up with him.
If he truly cares about you, the idea of losing you may be the jolt he needs to start taking you seriously.
If breaking up with him doesn’t cause any changes in his behavior, then you are better off.
It is best to be free of him than to be used.