I feel terrible after my tennis lessons

It feels more like training than a lesson.
Before the lesson starts, I do some serve practice,
and once the lesson begins, we hit some forehands at the front.
Then we move to the back to hit forehands, topspin forehands, backhands, forehand-backhand combinations, and rallies.
When it's over, we move into volley practice,
but I'm already completely exhausted,
so even volleying is extremely difficult.
First of all, the tempo is too fast. It's so fast that if my form breaks,
they immediately point out my posture. It's only 20 minutes, but after playing,
my clothes are soaked in sweat and I'm totally worn out.
I watch professional matches on YouTube,
and during the time they serve, they exchange rallies,
which provides at least a little bit of a break.
But when my coach rallies with me,
if a ball is even slightly difficult to hit, he doesn't let it pass;
he just feeds balls at a crazy speed, constantly all over the place.
I take these lessons every weekend morning, and after playing,
it takes me several hours to recover.
Is this really right? I want to improve my skills, of course,
but I'm doing this because I want to enjoy it as a hobby.