My boyfriend asked me not to send him a lot of messages every day, which made me a little bit hard. What does that mean?

This may be because your boyfriend wants you to leave him some personal space and time, and hopes that the relationship between you will be more balanced.

When you send him a lot of messages, it may make him feel a little stressed, because he needs to reply to every message, which may take up his time and make him feel a little tired.

Therefore, your boyfriend may want you to control your information and give him more time to do his own thing, hoping that your relationship will be more equal and natural. However, it doesn't necessarily mean that he doesn't care about you or doesn't like you. He may want to make your relationship healthier in this way.