This is something that I've been grappling with every year. Some students, no matter how hard I try, refuse to count their beats. They are usually the ones who really need to because they are struggling and need help with the rhythm or the tempo.

As far as I can tell, my students fall into five general groups. Perhaps you're in one of them:

Students who hope that their rhythmic instability isn't so obvious if they don't count,
Students who are self-conscious and don't like to hear their voice,
Students who just don't care about whether they are playing the rhythm correctly, and
Students who aren't sure how to count beats in their music.

Well students, regardless of whether you count, we music teachers can tell when the timing is off.

For my students who are self-conscious, sometimes, I count out loud with them or bang out the beat on my cajón. You could ask a family member to count with you at home (just ask them to be steady like a clock and then set the metronome to what the tick-tocks should be).

For the students who are apathetic about rhythm, there isn't much that me or your music teacher can do to help you. You've probably heard it before, you just can't help someone who doesn't want help in the first place.

Now for those of you who need a refresher on how to count, I have found these articles and video tutorials: